bikerburgess Posted June 24, 2014 Share Posted June 24, 2014 So the energy going one way is not necessarily the same as the energy of the bullet is not necessarily the same as the energy in the pistol? Wow that is interesting Sent from my SAMSUNG-SM-N900A using Tapatalk Link to comment Share on other sites More sharing options...
peterthefish Posted June 24, 2014 Share Posted June 24, 2014 (edited) So the energy going one way is not necessarily the same as the energy of the bullet is not necessarily the same as the energy in the pistol? Wow that is interesting Sent from my SAMSUNG-SM-N900A using Tapatalk Momentum <> Energy. Groundbreaking stuff.Almost like a 55 grain 5.56 at 3000 FPS with the same 165 PF as a 200 GR .45 ACP moving at 825 FPS has more energy... I bet it recoils more too! We might be on to something here... Also known as, something slow and heavy may have the same momentum but less energy than something fast and light. /Quick, someone check google and make sure the rifle round actually has more energy?! I've used up my tubes for tonight and I don't think anyone here shoots rifle. //Paging someone who knows more about physics than how to spell it... Edited June 24, 2014 by peterthefish Link to comment Share on other sites More sharing options...
bikerburgess Posted June 24, 2014 Share Posted June 24, 2014 So if I build a rig and fire a 223 one way and a 45 the other the rig will remain stationary because the momentum is the same or will it move away from the 223 muzzle because the energy in that direction greater? Sent from my SAMSUNG-SM-N900A using Tapatalk Link to comment Share on other sites More sharing options...
peterthefish Posted June 24, 2014 Share Posted June 24, 2014 So if I build a rig and fire a 223 one way and a 45 the other the rig will remain stationary because the momentum is the same or will it move away from the 223 muzzle because the energy in that direction greater? Sent from my SAMSUNG-SM-N900A using Tapatalk You have been provided with the tools. You tell me. Link to comment Share on other sites More sharing options...
MikeRush Posted June 24, 2014 Share Posted June 24, 2014 I love the internet where you can witness an ultimate smackdown between Googlesearch and someone actually trained in what the argument is about and nobody goes WTF??. Qualification sur la base de Google ne sont pas vraiment des compétences à tous. (I speak GoogleFrench but couldn't discuss the subtleties of Candide with Voltaire in his native tongue. ) Then again, maybe it is just me. Its been a long day.... This. If you are going to bring up the first thing that pops up in Google you might want to take another second or two and study "free recoil". I don't think that formula means what you think it means, at least not if you hold your gun while firing it like most practical pistol shooters do. Mr. Cheely clearly paid attention in class. Actually, not that. Free recoil is a measure of kinetic energy translated to the shooter. While it's all well and good to say "I'm Matt Cheely, Newton's 3rd law, BAM!" that analysis fails basic rigor, and I'm surprised any engineer (even a non-mechanical engineer) doesn't immediately see that. Let's dig in a bit, starting with the concept of conservation of momentum. Assume that the firearm is a closed system. Once the gun has been fired, you have two particles with momentum conserved. We'll assume that the forces are purely oppositve vectors (i.e. gun is not torquing but recoils straight back). One particle is the bullet (for simplicity sake m1 = 1 and v1 = 100) and the other is the handgun (again for simplicity, m2 = 100, v2 = 1). Momentum is conserved; m1v1 = m2v2. Now let's add 10% to the weight of the handgun. Holding that the increase in weight does not change the velocity of the bullet (it does not - that is dictated by the energy in the powder charge) the equation is now m1v1 = m2v2 or 1 * 100 = 110 * x. Solving for x, the velocity of the firearm (v2) is now .91. Ah, you say! See, the shooter still absorbs net momentum of 1! It just changes the recoil impulse. But let's move a bit further in the analysis. Is the collision (in a physics sense) between the shooter and the firearm elastic, inelastic, or somewhere in between? I would imagine most elite shooters (vs. simple internet commandos like myself) would like to imagine that the collision is perfectly inelastic - they are the firearm, and the firearm doesn't dare recoil unless given permission. In this case, the recoil impulse, or momentum, is all that matters. If we were to step into reality, the collision or interaction between the shooter is partially elastic, and so we must also take into account the kinetic energy of the recoiling firearm. In the first case (with the unweighted firearm), the recoiling firearm has a KE = 1/2m1v1^2 = 50. In the second case (with a weighted firearm) it has a KE = 1/2m2v2^2 = 45.5. While a firm grip and good technique may minimize the difference here (bringing the collision closer to the inelastic side of things) it does not objectively eliminate it, nor make it only a matter of 'feel'. Why it is taken as gospel that the objectively softest recoiling loads are those with a heavy bullet / relatively low speed (at a given PF vs. a light bullet / high speed, compensators aside) while the same concept, when applied to the firearm (which is no less a projectile than the bullet in the system of a fired gun) is subject to debate, is beyond me. /Internet commando out. Please explain to me how FREE recoil energy is relevant? I am have read your posts and you have not satisfactorily addressed this point. Throwing around phrases like "fails basic rigor" is something you say when you have your stuff sorted out. Using terms like inelastic in conjunction with the hyperbole "the firearm doesn't dare recoil unless given permission" (which would be a clear violation of Newton's 3rd law) does not mean that your calculation has become relevant. Let's take your assumption that our shooter somehow has figured out a way to aim and fire a gun without holding or being in contact with it, and that after firing a shot with it in the air he catches it (for your kinetic energy calculation to be applicable, the firearm would need to be as free to travel as the bullet before that kinetic energy is "translated to the shooter") - your calculation demonstrates that a 10% increase in the mass of the firearm yields less than a 10% reduction in kinetic energy. Great, you can have your internet cookie. Is it worth it on the clock? Meanwhile, Mr. Cheely is building guns for GMs, you know, the guys that hold their guns and make holes where they want them. They understand that the firearm has to be merged into an acceptable sight picture as quickly as possible, and that excessive weight is not conducive to this. Steel Challenge guns are an example of this- they tend to be very light and transition very quickly. On the other end of the spectrum you have a benchrest gun (which if you could completely eliminate friction, leveled the firearm perfectly, and were not in contact with it, as some benchresters shoot- would achieve the free recoil kinetic energy you calculated) that is fired at a single target repeatedly. Practical shooting, particularly while using a major power factor non-compensated gun, would be in between- we generally take two shots on paper and one on steel. What is the ideal gun weight? It depends- Bob Londrigan has suggested that a more experienced shooter will benefit from a lighter pistol, as the recoil is acceptable and the gun will be more responsive to the shooter's inputs. With the lowering of the power factor, the mathematically "ideal" gun weight is likewise reduced- bringing us back to those light Steel Challenge guns with very light ammo. IPSC has a higher minimum power factor than USPSA, meaning that in theory the IPSC "ideal" gun weight might be higher than that of a USPSA pistol. With all that being said, this is a thread about tungsten barrels, and jediwarrior and bonglee have provided some input on how the gun "feels". If the weight, particularly the weight at the front of the gun is worth accelerating and decelerating to targets on the clock we should see that at the World Shoot and the tungsten barrel become the "hot" setup internationally. Sincerely, a ME dropout who has measured stage performance with a timer, and found his original perception on gun weight and performance (for him) was incorrect Link to comment Share on other sites More sharing options...
peterthefish Posted June 24, 2014 Share Posted June 24, 2014 (edited) Free recoil is relevant because that's the force the shooter has to absorb. All other things being equal, less is better (or more conducive to shooting on the clock). The idea that someone holding a gun means that free recoil no longer exists or is applicable is silly. Nor does the firearm have to be free floating and caught for KE to come into effect. Unless the firearm is fused to the shooter the KE is transmitted to the shooter through impact. As I noted, a firm grip mitigates some of this. Perhaps instead of a 10% reduction in recoil you'll only get 5%. Do you load your ammo 5% over a safe PF for S&Gs? It's not a matter of your opinion or how awesome anyone is - it's a fact. Heavier gun = less recoil transmitted to shooter. Whether or not you perceive a heavy gun or light gun to swing or track better, more weight forward to cause a gun to dive rather than stay flat, or think that new CFE Load is gonna help you make GM, a heavier gun transmits less recoil. /Glad you dropped out - PE creds usually require you to put fact ahead of opinion, and do the math instead of just doing what you feel is right. //A law school dropout. OK, I didn't drop out, but I thought really hard about applying. Edited June 24, 2014 by peterthefish Link to comment Share on other sites More sharing options...
MikeRush Posted June 24, 2014 Share Posted June 24, 2014 Free recoil is relevant because that's the force the shooter has to absorb. All other things being equal, less is better (or more conducive to shooting on the clock). The idea that someone holding a gun means that free recoil no longer exists or is applicable is silly. Nor does the firearm have to be free floating and caught for KE to come into effect. Unless the firearm is fused to the shooter the KE is transmitted to the shooter through impact. As I noted, a firm grip mitigates some of this. Perhaps instead of a 10% reduction in recoil you'll only get 5%. Do you load your ammo 5% over a safe PF for S&Gs? It's not a matter of your opinion or how awesome anyone is - it's a fact. Heavier gun = less recoil transmitted to shooter. Whether or not you perceive a heavy gun or light gun to swing or track better, more weight forward to cause a gun to dive rather than stay flat, or think that new CFE Load is gonna help you make GM, a heavier gun transmits less recoil. /Glad you dropped out - PE creds usually require you to put fact ahead of opinion, and do the math instead of just doing what you feel is right. //A law school dropout. OK, I didn't drop out, but I thought really hard about applying. 2 Internet cookies? Please address the "free" part of free recoil. I am quite glad I changed majors as well. Thanks for the support! I have a successful career doing what I love, and I still get to use calculus! The whole "fact ahead of opinion" thing is so two sided- it is your opinion that the only masses relevant in the equation are the bullet and the gun. The rest of us hold it. If you want to do some math instead of just doing what you feel is right, consider an additional mass in your theoretical system- one between 50-100 times greater than the gun itself. Obviously I wouldn't have the audacity to suggest my hands are as solid as planting a mortar into the earth, but I would humbly submit that my grip is more similar to that, than the gun floating in air. Want real cookies? Take your brick to Nationals or the World Shoot and win. You obviously know something most of the shooting world doesn't. If you will excuse me, I am going to go dryfire. Feel free to beat your chest. Physics (outside of the simplified, 2 mass middle school variant) still applies. Link to comment Share on other sites More sharing options...
feederic Posted June 25, 2014 Share Posted June 25, 2014 (edited) I didn't have enough time to go get my Bachelors so I just Googled it. http://www.saami.org/PubResources/GunRecoilFormulae.pdf Lets figure out that FRE equation you provided. If we assume a limited gun weighing 38 oz, 180gr bullet at 175pf, we get 4.237 ft/lb. Add 3oz onto the weight of the gun, and we get 3.927 ft/lb. That's a ~7.5% decrease in kinetic energy. That's only for a free recoiling firearm. ie, one that isn't being held. Yes, the lighter gun will have more kinetic energy after a given distance traveled than the heavy gun, in the same way the lighter can has more kinetic energy than the heavy can at the same height. But you're there to hold the gun, so the energy is transferred into you instead. We're still just changing the way the energy (recoil) is felt. Not to mention, this is just calculating F.R.E. based on the total weight of the gun. So you had better hang your 12oz can of paint from the grip so the recoil is "less", it'll work better than the tungsten barrel. Or: If the recoil is "less" where did that energy go if not into your hands? http://en.wikipedia.org/wiki/Conservation_of_energy With a heavier gun, and according to the FRE formula, there is simply less free recoil energy for any given set bullet and charge. The weight of the gun needs work applied to it before it will move, heavier objects move slower versus a lighter object when given the same amount of energy. That's why free recoil is less for a heavier gun. If one is saying free recoil doesn't matter, that is also saying the weight of the bullet, powder charge, and weight of the gun doesn't matter either. And if they did not matter, I doubt we would have subforums here dedicated to reloading with special pet recipes as well as a surge in steel grips making their way onto shooter's platforms right now. Heavy barrels do an excellent job at dampening recoil because they subtract energy transferred to the slide which lessens its impact force on the frame. Edited June 25, 2014 by feederic Link to comment Share on other sites More sharing options...
feederic Posted June 25, 2014 Share Posted June 25, 2014 (edited) Free recoil is relevant because that's the force the shooter has to absorb. All other things being equal, less is better (or more conducive to shooting on the clock). The idea that someone holding a gun means that free recoil no longer exists or is applicable is silly. Nor does the firearm have to be free floating and caught for KE to come into effect. Unless the firearm is fused to the shooter the KE is transmitted to the shooter through impact. As I noted, a firm grip mitigates some of this. Perhaps instead of a 10% reduction in recoil you'll only get 5%. Do you load your ammo 5% over a safe PF for S&Gs? It's not a matter of your opinion or how awesome anyone is - it's a fact. Heavier gun = less recoil transmitted to shooter. Whether or not you perceive a heavy gun or light gun to swing or track better, more weight forward to cause a gun to dive rather than stay flat, or think that new CFE Load is gonna help you make GM, a heavier gun transmits less recoil. /Glad you dropped out - PE creds usually require you to put fact ahead of opinion, and do the math instead of just doing what you feel is right. //A law school dropout. OK, I didn't drop out, but I thought really hard about applying. 2 Internet cookies? Please address the "free" part of free recoil. I am quite glad I changed majors as well. Thanks for the support! I have a successful career doing what I love, and I still get to use calculus! The whole "fact ahead of opinion" thing is so two sided- it is your opinion that the only masses relevant in the equation are the bullet and the gun. The rest of us hold it. If you want to do some math instead of just doing what you feel is right, consider an additional mass in your theoretical system- one between 50-100 times greater than the gun itself. Obviously I wouldn't have the audacity to suggest my hands are as solid as planting a mortar into the earth, but I would humbly submit that my grip is more similar to that, than the gun floating in air. Want real cookies? Take your brick to Nationals or the World Shoot and win. You obviously know something most of the shooting world doesn't. If you will excuse me, I am going to go dryfire. Feel free to beat your chest. Physics (outside of the simplified, 2 mass middle school variant) still applies. Care to elaborate on how free recoil doesn't matter? If I had two firearms, one with an incredibly large amount of free recoil and another with an immeasurable amount, which would you want to grab onto? According to the FRE formula, mass of the bullet and its velocity affect the result. Would you say that a 250 pf round does not feel more harsh than one loaded to the minor floor? In general, it states heavier guns and lower PF rounds shoot softer. I agree. Jediwarrior's tungsten barrel does a great job at increasing weight of the barrel, while also decreasing slide weight. Knowing the results of switching from a bushing to a bull barrel in my limited gun, I would love to try his setup. Edited June 25, 2014 by feederic Link to comment Share on other sites More sharing options...
MikeRush Posted June 25, 2014 Share Posted June 25, 2014 Free recoil is relevant because that's the force the shooter has to absorb. All other things being equal, less is better (or more conducive to shooting on the clock). The idea that someone holding a gun means that free recoil no longer exists or is applicable is silly. Nor does the firearm have to be free floating and caught for KE to come into effect. Unless the firearm is fused to the shooter the KE is transmitted to the shooter through impact. As I noted, a firm grip mitigates some of this. Perhaps instead of a 10% reduction in recoil you'll only get 5%. Do you load your ammo 5% over a safe PF for S&Gs? It's not a matter of your opinion or how awesome anyone is - it's a fact. Heavier gun = less recoil transmitted to shooter. Whether or not you perceive a heavy gun or light gun to swing or track better, more weight forward to cause a gun to dive rather than stay flat, or think that new CFE Load is gonna help you make GM, a heavier gun transmits less recoil. /Glad you dropped out - PE creds usually require you to put fact ahead of opinion, and do the math instead of just doing what you feel is right. //A law school dropout. OK, I didn't drop out, but I thought really hard about applying. 2 Internet cookies? Please address the "free" part of free recoil. I am quite glad I changed majors as well. Thanks for the support! I have a successful career doing what I love, and I still get to use calculus! The whole "fact ahead of opinion" thing is so two sided- it is your opinion that the only masses relevant in the equation are the bullet and the gun. The rest of us hold it. If you want to do some math instead of just doing what you feel is right, consider an additional mass in your theoretical system- one between 50-100 times greater than the gun itself. Obviously I wouldn't have the audacity to suggest my hands are as solid as planting a mortar into the earth, but I would humbly submit that my grip is more similar to that, than the gun floating in air. Want real cookies? Take your brick to Nationals or the World Shoot and win. You obviously know something most of the shooting world doesn't. If you will excuse me, I am going to go dryfire. Feel free to beat your chest. Physics (outside of the simplified, 2 mass middle school variant) still applies. Care to elaborate on how free recoil doesn't matter? If I had two firearms, one with an incredibly large amount of free recoil and another with an immeasurable amount, which would you want to grab onto? According to the FRE formula, mass of the bullet and its velocity affect the result. Would you say that a 250 pf round does not feel more harsh than one loaded to the minor floor? In general, it states heavier guns and lower PF rounds shoot softer. I agree. Jediwarrior's tungsten barrel does a great job at increasing weight of the barrel, while also decreasing slide weight. Knowing the results of switching from a bushing to a bull barrel in my limited gun, I would love to try his setup. I'm about ready to hang up the hat on the physics discussions, as nobody seems to want to have a reasonable discussion- everyone keeps pointing to the existence of a free recoil formula as justification for its relevance to this application. The free recoil kinetic energy formula is completely correct if you are considering a 2 mass system involving only the firearm and the projectile. Where is the weight/strength of the shooter in the free recoil equation? It isn't there because it is not factored into the equation. It is too difficult to quantify, so the equation is called the FREE recoil equation, or, the kinetic energy imparted to a gun fired floating in space. Will you argue that the rearward velocity and travel of a Glock loaded to major fired by Bob Vogel and one fired by a six year old girl is the same? Why not? Per the free recoil equation it still has the same amount of kinetic energy and velocity. I would suggest that the arms and body introduce a third mass that is initially in contact with the firearm effectively adding to the mass of the system opposing the launch of the bullet. If you disagree with that then I would ask you to justify, but at this point I really don't care. If one were interested enough he could use high speed videography to determine the velocity of a fired gun, and see if it would match the velocity in the FRE. I would suggest that it would not. Adding the mass of the shooter (yes, even considering that the shooter is not a completely rigid body) to the weight of the firearm leaves a reasonable increase in overall weight of the firearm as being relatively insignificant (in terms of the overall system). This leaves us with the momentum imparted by the launch of the projectile, which is determined by the mass (including propellent ejecta, that is where your pet loads come in) and velocity. Think about it this way, is your limited gun a pussycat with a loaded mag but an unruly beast by the time your mag runs dry? Try weighing a loaded up a limited mag, plugging that in as your delta, and checking the results of the FRE as a percentage, and tell me if you think it is reasonable. I will agree that a 250 pf rd will feel more harsh than a minor round. That is a bit of a red herring as it has to do with the the mass and velocity of the projectile rather than anything to do with the weight of the gun. I agree that heavier guns and lower PF rounds shoot "softer", but not because of the free recoil equation. Overall, momentum is conserved, a heavier gun will feel softer at a given power factor because the velocity of the gun is reduced and not because there is any less energy in our fired shot (back to Newton's 3rd). If you disagree that is totally fine by me. I've only tried to apply proper physics to this thread as some pretty wild numbers have been thrown out. Eppur si muove. Setting aside overall weight for a moment, as I believe an increase is less beneficial than some would think- Would a 38 oz tungsten barreled gun feel softer than a 38 oz bushing barreled gun? I absolutely think so. A semiautomatic pistol is still not a 2 particle system. The firing of shot introduces rearward momentum to the barrel, that unlocks it from the slide and in turn imparts momentum to the slide. This would spread the impulse transmitted to the shooter out over a longer period of time which will feel softer. That is why I have expressed interest in the tungsten barrels, slide weight, etc and I am keeping a close eye on this thread. It fascinates me. It might be the wave of the future. It might not. Until more people have them, practice with them, and shoot them at majors we won't know. This is why a 36 oz bull barreled limited gun feels softer than a 36 oz bushing barreled gun, at least to my hands with the same ammo. Can this reconcile the anecdotal with the scientific? I hope so. If I had the money I would consider commissioning jediwarrior (who I respect immensely, and consider to be a cutting edge gunsmith when it comes to tungsten- he has taken the time to send me PMs with additional information related to his builds) to build a jumbo tungsten barreled gun with a 10 oz or less slide and a titanium frame as an experiment. I like a light gun overall, but I think that the distribution of it will have a big impact on how easy the gun is to shoot. Lots of thoughts on reciprocating mass in the slide, but I think that setup would yield minimal reciprocating mass without ridiculously high slide velocities, which can compromise reliability (mags can't keep up, BTDT). Heavier guns seem easier to shoot well. The prolonged recoil impulse helps prevent flinching, makes sight tracking/shot calling easier, and the higher overall weight makes it feel more stable in the hands. At some point a shooter can be comfortable with a lighter gun, keeping in mind we want to minimize our splits AND transitions. Frankly, if there is at least one piece of steel, and no more than 2 shots per paper we have more transitions than splits in a course of fire. I shot a stock Glock 24 for a while which gave me excellent transitions and results in steel challenge style matches that I have not yet been able to equal with a heavier 2011, but the 2011 is an easier ride around a field course and yields faster splits for me. My upcoming build will have a relatively high amount of the overall weight in the barrel, a light slide, and light frame. Link to comment Share on other sites More sharing options...
bonglee0507 Posted June 25, 2014 Share Posted June 25, 2014 Free recoil is relevant because that's the force the shooter has to absorb. All other things being equal, less is better (or more conducive to shooting on the clock). The idea that someone holding a gun means that free recoil no longer exists or is applicable is silly. Nor does the firearm have to be free floating and caught for KE to come into effect. Unless the firearm is fused to the shooter the KE is transmitted to the shooter through impact. As I noted, a firm grip mitigates some of this. Perhaps instead of a 10% reduction in recoil you'll only get 5%. Do you load your ammo 5% over a safe PF for S&Gs? It's not a matter of your opinion or how awesome anyone is - it's a fact. Heavier gun = less recoil transmitted to shooter. Whether or not you perceive a heavy gun or light gun to swing or track better, more weight forward to cause a gun to dive rather than stay flat, or think that new CFE Load is gonna help you make GM, a heavier gun transmits less recoil. /Glad you dropped out - PE creds usually require you to put fact ahead of opinion, and do the math instead of just doing what you feel is right. //A law school dropout. OK, I didn't drop out, but I thought really hard about applying. 2 Internet cookies? Please address the "free" part of free recoil. I am quite glad I changed majors as well. Thanks for the support! I have a successful career doing what I love, and I still get to use calculus! The whole "fact ahead of opinion" thing is so two sided- it is your opinion that the only masses relevant in the equation are the bullet and the gun. The rest of us hold it. If you want to do some math instead of just doing what you feel is right, consider an additional mass in your theoretical system- one between 50-100 times greater than the gun itself. Obviously I wouldn't have the audacity to suggest my hands are as solid as planting a mortar into the earth, but I would humbly submit that my grip is more similar to that, than the gun floating in air. Want real cookies? Take your brick to Nationals or the World Shoot and win. You obviously know something most of the shooting world doesn't. If you will excuse me, I am going to go dryfire. Feel free to beat your chest. Physics (outside of the simplified, 2 mass middle school variant) still applies. Care to elaborate on how free recoil doesn't matter? If I had two firearms, one with an incredibly large amount of free recoil and another with an immeasurable amount, which would you want to grab onto? According to the FRE formula, mass of the bullet and its velocity affect the result. Would you say that a 250 pf round does not feel more harsh than one loaded to the minor floor? In general, it states heavier guns and lower PF rounds shoot softer. I agree. Jediwarrior's tungsten barrel does a great job at increasing weight of the barrel, while also decreasing slide weight. Knowing the results of switching from a bushing to a bull barrel in my limited gun, I would love to try his setup. I'm about ready to hang up the hat on the physics discussions, as nobody seems to want to have a reasonable discussion- everyone keeps pointing to the existence of a free recoil formula as justification for its relevance to this application. The free recoil kinetic energy formula is completely correct if you are considering a 2 mass system involving only the firearm and the projectile. Where is the weight/strength of the shooter in the free recoil equation? It isn't there because it is not factored into the equation. It is too difficult to quantify, so the equation is called the FREE recoil equation, or, the kinetic energy imparted to a gun fired floating in space. Will you argue that the rearward velocity and travel of a Glock loaded to major fired by Bob Vogel and one fired by a six year old girl is the same? Why not? Per the free recoil equation it still has the same amount of kinetic energy and velocity. I would suggest that the arms and body introduce a third mass that is initially in contact with the firearm effectively adding to the mass of the system opposing the launch of the bullet. If you disagree with that then I would ask you to justify, but at this point I really don't care. If one were interested enough he could use high speed videography to determine the velocity of a fired gun, and see if it would match the velocity in the FRE. I would suggest that it would not. Adding the mass of the shooter (yes, even considering that the shooter is not a completely rigid body) to the weight of the firearm leaves a reasonable increase in overall weight of the firearm as being relatively insignificant (in terms of the overall system). This leaves us with the momentum imparted by the launch of the projectile, which is determined by the mass (including propellent ejecta, that is where your pet loads come in) and velocity. Think about it this way, is your limited gun a pussycat with a loaded mag but an unruly beast by the time your mag runs dry? Try weighing a loaded up a limited mag, plugging that in as your delta, and checking the results of the FRE as a percentage, and tell me if you think it is reasonable. I will agree that a 250 pf rd will feel more harsh than a minor round. That is a bit of a red herring as it has to do with the the mass and velocity of the projectile rather than anything to do with the weight of the gun. I agree that heavier guns and lower PF rounds shoot "softer", but not because of the free recoil equation. Overall, momentum is conserved, a heavier gun will feel softer at a given power factor because the velocity of the gun is reduced and not because there is any less energy in our fired shot (back to Newton's 3rd). If you disagree that is totally fine by me. I've only tried to apply proper physics to this thread as some pretty wild numbers have been thrown out. Eppur si muove. Setting aside overall weight for a moment, as I believe an increase is less beneficial than some would think- Would a 38 oz tungsten barreled gun feel softer than a 38 oz bushing barreled gun? I absolutely think so. A semiautomatic pistol is still not a 2 particle system. The firing of shot introduces rearward momentum to the barrel, that unlocks it from the slide and in turn imparts momentum to the slide. This would spread the impulse transmitted to the shooter out over a longer period of time which will feel softer. That is why I have expressed interest in the tungsten barrels, slide weight, etc and I am keeping a close eye on this thread. It fascinates me. It might be the wave of the future. It might not. Until more people have them, practice with them, and shoot them at majors we won't know. This is why a 36 oz bull barreled limited gun feels softer than a 36 oz bushing barreled gun, at least to my hands with the same ammo. Can this reconcile the anecdotal with the scientific? I hope so. If I had the money I would consider commissioning jediwarrior (who I respect immensely, and consider to be a cutting edge gunsmith when it comes to tungsten- he has taken the time to send me PMs with additional information related to his builds) to build a jumbo tungsten barreled gun with a 10 oz or less slide and a titanium frame as an experiment. I like a light gun overall, but I think that the distribution of it will have a big impact on how easy the gun is to shoot. Lots of thoughts on reciprocating mass in the slide, but I think that setup would yield minimal reciprocating mass without ridiculously high slide velocities, which can compromise reliability (mags can't keep up, BTDT). Heavier guns seem easier to shoot well. The prolonged recoil impulse helps prevent flinching, makes sight tracking/shot calling easier, and the higher overall weight makes it feel more stable in the hands. At some point a shooter can be comfortable with a lighter gun, keeping in mind we want to minimize our splits AND transitions. Frankly, if there is at least one piece of steel, and no more than 2 shots per paper we have more transitions than splits in a course of fire. I shot a stock Glock 24 for a while which gave me excellent transitions and results in steel challenge style matches that I have not yet been able to equal with a heavier 2011, but the 2011 is an easier ride around a field course and yields faster splits for me. My upcoming build will have a relatively high amount of the overall weight in the barrel, a light slide, and light frame. Jediwarrior is my gunsmith! Link to comment Share on other sites More sharing options...
peterthefish Posted June 25, 2014 Share Posted June 25, 2014 (edited) [/font][/color] Adding the mass of the shooter (yes, even considering that the shooter is not a completely rigid body) to the weight of the firearm leaves a reasonable increase in overall weight of the firearm as being relatively insignificant (in terms of the overall system). This leaves us with the momentum imparted by the launch of the projectile, which is determined by the mass (including propellent ejecta, that is where your pet loads come in) and velocity. Think about it this way, is your limited gun a pussycat with a loaded mag but an unruly beast by the time your mag runs dry? Try weighing a loaded up a limited mag, plugging that in as your delta, and checking the results of the FRE as a percentage, and tell me if you think it is reasonable. I will agree that a 250 pf rd will feel more harsh than a minor round. That is a bit of a red herring as it has to do with the the mass and velocity of the projectile rather than anything to do with the weight of the gun. I agree that heavier guns and lower PF rounds shoot "softer", but not because of the free recoil equation. Overall, momentum is conserved, a heavier gun will feel softer at a given power factor because the velocity of the gun is reduced and not because there is any less energy in our fired shot (back to Newton's 3rd). If you disagree that is totally fine by me. I've only tried to apply proper physics to this thread as some pretty wild numbers have been thrown out. Eppur si muove.[/font][/color] 1. You cannot add the mass of the shooter to the equation unless the firearm and the shooter are coupled. They are not. Like most facts, this is not subject to your opinion. 2. In fact most guns do have less felt recoil with a fully loaded mag, but since you do your physics 'on the clock' you probably don't notice. Over and above that, much of felt recoil is torque from a force applied at the bore axis which is higher than the grip. Adding weight in line with the bore axis will have a greater impact. 3. You are correct about one thing. A semi-automatic gun is a complex system and many things impact the transmission of momentum. Hence why I noted "all other things being equal" a heavier gun recoils less. 4. So you agree with the result the free recoil equation gives (I agree that heavier guns and lower PF rounds shoot "softer") but don't think the equation applies? You agree that a "heavier gun will feel softer at a given power factor because the velocity of the gun is reduced" but don't think that the accompanying reduction in kinetic energy of the recoiling firearm is relevant? I noted in an earlier post why (for example the percentage) recoil reduction given by the FRE is not the beginning and end of recoil reduction. But it is the beginning. Any other places where your personal opinion overpowers some basic math and physical laws? And you call that trying to bring "proper physics" to the thread? Stick to what you know. Clearly this ain't it. /I've noticed the more gas I put in my car the further it goes. Someone who doesn't drive as much as me told me it's because more gas means more energy means more distance, but adding more gas makes the car heavier so in my opinion he's wrong. That's pretty much where you stand in this whole thing. Edited June 25, 2014 by peterthefish Link to comment Share on other sites More sharing options...
Akkid17 Posted June 25, 2014 Share Posted June 25, 2014 This pretty much sums up what this turned into. I hope you enjoy it as much as I did. Link to comment Share on other sites More sharing options...
peterthefish Posted June 25, 2014 Share Posted June 25, 2014 This pretty much sums up what this turned into. I hope you enjoy it as much as I did. I love XKCD (thought of sending this in as a 'What If' topic but I'm not sure if a rocket scientist's word will have any more of an effect on his opinion than mine. Link to comment Share on other sites More sharing options...
MikeRush Posted June 25, 2014 Share Posted June 25, 2014 [/font][/color] Adding the mass of the shooter (yes, even considering that the shooter is not a completely rigid body) to the weight of the firearm leaves a reasonable increase in overall weight of the firearm as being relatively insignificant (in terms of the overall system). This leaves us with the momentum imparted by the launch of the projectile, which is determined by the mass (including propellent ejecta, that is where your pet loads come in) and velocity. Think about it this way, is your limited gun a pussycat with a loaded mag but an unruly beast by the time your mag runs dry? Try weighing a loaded up a limited mag, plugging that in as your delta, and checking the results of the FRE as a percentage, and tell me if you think it is reasonable. I will agree that a 250 pf rd will feel more harsh than a minor round. That is a bit of a red herring as it has to do with the the mass and velocity of the projectile rather than anything to do with the weight of the gun. I agree that heavier guns and lower PF rounds shoot "softer", but not because of the free recoil equation. Overall, momentum is conserved, a heavier gun will feel softer at a given power factor because the velocity of the gun is reduced and not because there is any less energy in our fired shot (back to Newton's 3rd). If you disagree that is totally fine by me. I've only tried to apply proper physics to this thread as some pretty wild numbers have been thrown out. Eppur si muove.[/font][/color] 1. You cannot add the mass of the shooter to the equation unless the firearm and the shooter are coupled. They are not. Like most facts, this is not subject to your opinion.2. In fact most guns do have less felt recoil with a fully loaded mag, but since you do your physics 'on the clock' you probably don't notice. Over and above that, much of felt recoil is torque from a force applied at the bore axis which is higher than the grip. Adding weight in line with the bore axis will have a greater impact. 3. You are correct about one thing. A semi-automatic gun is a complex system and many things impact the transmission of momentum. Hence why I noted "all other things being equal" a heavier gun recoils less. 4. So you agree with the result the free recoil equation gives (I agree that heavier guns and lower PF rounds shoot "softer") but don't think the equation applies? You agree that a "heavier gun will feel softer at a given power factor because the velocity of the gun is reduced" but don't think that the accompanying reduction in kinetic energy of the recoiling firearm is relevant? I noted in an earlier post why (for example the percentage) recoil reduction given by the FRE is not the beginning and end of recoil reduction. But it is the beginning. Any other places where your personal opinion overpowers some basic math and physical laws? And you call that trying to bring "proper physics" to the thread? Stick to what you know. Clearly this ain't it. /I've noticed the more gas I put in my car the further it goes. Someone who doesn't drive as much as me told me it's because more gas means more energy means more distance, but adding more gas makes the car heavier so in my opinion he's wrong. That's pretty much where you stand in this whole thing. I'm going to leave you with a couple of thoughts, then I am out. I admittedly am not an internet commando, so I am not used to saying the same thing over and over again until someone gives up trying to reason with me, but I disagree with the application of the FREE recoil equation and the resultant energy differential between a light and heavy gun USPSA as being significant in terms of "energy". I maintain that it is a perception of the transfer of momentum. The recoil impulse is spread out over a greater period of time. A heavier gun may travel rearward slower upon firing, but the end result is that it will also be more mass traveling rearward that the shooter is applying force against. This is a slower and therefore "softer feeling" recoil event. Please justify the use of the FREE recoil equation. You say that the shooter and the firearm are not coupled. This must be true for your equation to hold. This is why you are so adamant about your findings. The reality is the shooter and the firearm ARE coupled. Or are they truly disconnected? A gun will FEEL slightly softer with a full mag than with an empty one due to the increased mass. This is because I believe the relevant measurement is momentum, and not the "kinetic energy" of the gun which is initially supported unlike in your FRE. Please consider the following: Glock 35 weighs about 27 oz. A limited mag loaded to capacity with 180s weighs 17.4 oz. A 180 gr load to 165 pf. Calculate the FREE recoil of the empty gun and the full gun, and give the delta as a percentage. If you can tell me with a straight face that is a reasonable approximation then I don't have anything else to say to you. If you are afraid of the result and won't do it, I will do it when I get home from work. You might want to fire up the engines of war and start "correcting" everything on the internet about conservation of momentum and recoil. I'm out. I don't need to be right on the interweb machine. Ill just keep on shooting my guns. Jediwarrior, keep up the great work. Link to comment Share on other sites More sharing options...
bonglee0507 Posted June 25, 2014 Share Posted June 25, 2014 [/font][/color] Adding the mass of the shooter (yes, even considering that the shooter is not a completely rigid body) to the weight of the firearm leaves a reasonable increase in overall weight of the firearm as being relatively insignificant (in terms of the overall system). This leaves us with the momentum imparted by the launch of the projectile, which is determined by the mass (including propellent ejecta, that is where your pet loads come in) and velocity. Think about it this way, is your limited gun a pussycat with a loaded mag but an unruly beast by the time your mag runs dry? Try weighing a loaded up a limited mag, plugging that in as your delta, and checking the results of the FRE as a percentage, and tell me if you think it is reasonable. I will agree that a 250 pf rd will feel more harsh than a minor round. That is a bit of a red herring as it has to do with the the mass and velocity of the projectile rather than anything to do with the weight of the gun. I agree that heavier guns and lower PF rounds shoot "softer", but not because of the free recoil equation. Overall, momentum is conserved, a heavier gun will feel softer at a given power factor because the velocity of the gun is reduced and not because there is any less energy in our fired shot (back to Newton's 3rd). If you disagree that is totally fine by me. I've only tried to apply proper physics to this thread as some pretty wild numbers have been thrown out. Eppur si muove.[/font][/color] 1. You cannot add the mass of the shooter to the equation unless the firearm and the shooter are coupled. They are not. Like most facts, this is not subject to your opinion.2. In fact most guns do have less felt recoil with a fully loaded mag, but since you do your physics 'on the clock' you probably don't notice. Over and above that, much of felt recoil is torque from a force applied at the bore axis which is higher than the grip. Adding weight in line with the bore axis will have a greater impact. 3. You are correct about one thing. A semi-automatic gun is a complex system and many things impact the transmission of momentum. Hence why I noted "all other things being equal" a heavier gun recoils less. 4. So you agree with the result the free recoil equation gives (I agree that heavier guns and lower PF rounds shoot "softer") but don't think the equation applies? You agree that a "heavier gun will feel softer at a given power factor because the velocity of the gun is reduced" but don't think that the accompanying reduction in kinetic energy of the recoiling firearm is relevant? I noted in an earlier post why (for example the percentage) recoil reduction given by the FRE is not the beginning and end of recoil reduction. But it is the beginning. Any other places where your personal opinion overpowers some basic math and physical laws? And you call that trying to bring "proper physics" to the thread? Stick to what you know. Clearly this ain't it. /I've noticed the more gas I put in my car the further it goes. Someone who doesn't drive as much as me told me it's because more gas means more energy means more distance, but adding more gas makes the car heavier so in my opinion he's wrong. That's pretty much where you stand in this whole thing. I'm going to leave you with a couple of thoughts, then I am out. I admittedly am not an internet commando, so I am not used to saying the same thing over and over again until someone gives up trying to reason with me, but I disagree with the application of the FREE recoil equation and the resultant energy differential between a light and heavy gun USPSA as being significant in terms of "energy". I maintain that it is a perception of the transfer of momentum. The recoil impulse is spread out over a greater period of time. A heavier gun may travel rearward slower upon firing, but the end result is that it will also be more mass traveling rearward that the shooter is applying force against. This is a slower and therefore "softer feeling" recoil event. Please justify the use of the FREE recoil equation. You say that the shooter and the firearm are not coupled. This must be true for your equation to hold. This is why you are so adamant about your findings. The reality is the shooter and the firearm ARE coupled. Or are they truly disconnected? A gun will FEEL slightly softer with a full mag than with an empty one due to the increased mass. This is because I believe the relevant measurement is momentum, and not the "kinetic energy" of the gun which is initially supported unlike in your FRE. Please consider the following: Glock 35 weighs about 27 oz. A limited mag loaded to capacity with 180s weighs 17.4 oz. A 180 gr load to 165 pf. Calculate the FREE recoil of the empty gun and the full gun, and give the delta as a percentage. If you can tell me with a straight face that is a reasonable approximation then I don't have anything else to say to you. If you are afraid of the result and won't do it, I will do it when I get home from work. You might want to fire up the engines of war and start "correcting" everything on the internet about conservation of momentum and recoil. I'm out. I don't need to be right on the interweb machine. Ill just keep on shooting my guns. Jediwarrior, keep up the great work. Visit us here in the PI man let's drink some lambanog hehe Link to comment Share on other sites More sharing options...
peterthefish Posted June 25, 2014 Share Posted June 25, 2014 I'm going to leave you with a couple of thoughts, then I am out. I admittedly am not an internet commando, so I am not used to saying the same thing over and over again until someone gives up trying to reason with me, but I disagree with the application of the FREE recoil equation and the resultant energy differential between a light and heavy gun USPSA as being significant in terms of "energy". I maintain that it is a perception of the transfer of momentum. The recoil impulse is spread out over a greater period of time. Force (which in the case of a recoiling firearm is Kinetic Energy) = 1/2mv^2. If you reduce velocity by 10% and increase mass by 10%, you reduce the Force generated by the firearm. You can disagree with it all you want, but as the saying goes, e=mc^2 isn't just a good idea, it's the law. A heavier gun may travel rearward slower upon firing, but the end result is that it will also be more mass traveling rearward that the shooter is applying force against. This is a slower and therefore "softer feeling" recoil event. No. Assuming ammo with the same PF is shot, the momentum of the recoiling firearm is the same, regardless of weight. The event is slower and thus less energetic, because the equation squares the velocity component, which means increases or decreases in velocity exponentially increase or decrease Force / Energy. Please justify the use of the FREE recoil equation. You say that the shooter and the firearm are not coupled. This must be true for your equation to hold. This is why you are so adamant about your findings. The reality is the shooter and the firearm ARE coupled. Or are they truly disconnected? This is like saying "Please justify the use of acceleration to measure the rate at which your vehicle's speed increases." It's the correct measure to apply to the system. There are three ways to model a firearm being shot. 1) The shooter and the gun are one (your position) 2) The gun floats until fired, the shooter then catches it (just silly) 3) The gun is relatively (compared to say, a Ransom rest bolted to a table) loosely coupled to the shooter. When the gun accelerates in the shooters hand when fired, the shooter must exert a corresponding force to keep the gun from going flying. So essentially we have an impact. Now, the impact is not perfectly elastic (gun bounces off you) so Kinetic Energy is not conserved. Lets model this as an inelastic collision. All Kinetic Energy of the firearm is lost, while momentum of the system is preserved. And, as we've previously established, a lighter firearm firing 165 PF ammo has greated KE than a heavier firearm firing 165 PF ammo. Of course, there's the whole pesky "energy can neither be created nor destroyed" thing, so where does the Kinetic Energy go? It compresses the flesh in your palms. It heats your hands through friction. It is absorbed by your muscles, tendons, etc... In other words, you feel it, as recoil. A gun will FEEL slightly softer with a full mag than with an empty one due to the increased mass. This is because I believe the relevant measurement is momentum, and not the "kinetic energy" of the gun which is initially supported unlike in your FRE. Please consider the following: Glock 35 weighs about 27 oz. A limited mag loaded to capacity with 180s weighs 17.4 oz. A 180 gr load to 165 pf. Calculate the FREE recoil of the empty gun and the full gun, and give the delta as a percentage. If you can tell me with a straight face that is a reasonable approximation then I don't have anything else to say to you. If you are afraid of the result and won't do it, I will do it when I get home from work. Go nuts, do it. Let me give you a hint - the Free Recoil of the full gun will be almost 40% lower. For the third time, FRE is the beginning, not the end of the discussion. The relation of the weight to the center of mass is also important. You might want to fire up the engines of war and start "correcting" everything on the internet about conservation of momentum and recoil. I prefer to think of this as a charity service, ending ignorance one shooter at a time. Like Make-a-Wish, but for idiots instead of kids with cancer. Link to comment Share on other sites More sharing options...
Neomet Posted June 25, 2014 Share Posted June 25, 2014 Will the next lessons be on the use of basic civility? Can't wait. Link to comment Share on other sites More sharing options...
StraightUp_OG Posted June 25, 2014 Share Posted June 25, 2014 Sure wish this thread was on doodie. Link to comment Share on other sites More sharing options...
a.roberts Posted June 25, 2014 Share Posted June 25, 2014 (edited) Is it just me or has there been a noticeable increase in the number of pudding pissing matches on this forum?Also, physics is nice and all, but I feel like you're trying to quantify something that is qualitative, i.e. a shooter's preference and perception. Edited June 25, 2014 by a.roberts Link to comment Share on other sites More sharing options...
MikeRush Posted June 25, 2014 Share Posted June 25, 2014 Sure wish this thread was on doodie. Why, because he could make more personal attacks on me there than here? If you can't address someone's points call them an idiot. Boosts your credibility, you know? I'm going to post some FRE calcs when when I get home and then bow out. Anyone who is interested can look at the numbers and decide for themselves. Link to comment Share on other sites More sharing options...
peterthefish Posted June 25, 2014 Share Posted June 25, 2014 Sure wish this thread was on doodie. Why, because he could make more personal attacks on me there than here?If you can't address someone's points call them an idiot. Boosts your credibility, you know? I'm going to post some FRE calcs when when I get home and then bow out. Anyone who is interested can look at the numbers and decide for themselves. I like to think that my personal attacks are forum independent. While you're at it perhaps you could could post a graph of FRE vs Caliber for common loads assuming a constant gun weight. I wonder if they would follow generally perceived levels of recoil (I.e. 44 > 357 > 45 > 9mm > .22). Probably not though. It's just a number that has no practical application. Link to comment Share on other sites More sharing options...
StraightUp_OG Posted June 25, 2014 Share Posted June 25, 2014 Looks like I touched a nerve. Sorry to offend I will retreat now. Link to comment Share on other sites More sharing options...
MikeRush Posted June 25, 2014 Share Posted June 25, 2014 Looks like I touched a nerve. Sorry to offend I will retreat now. None taken. Just curious as to the reasoning. I love your CNC thread and builds! Link to comment Share on other sites More sharing options...
StraightUp_OG Posted June 25, 2014 Share Posted June 25, 2014 (edited) Thanks man good luck with your conversion and builds. Your machine will be the bomb once up and running. Making chips is one of the most gratifying things I have done. *Hijack off* Edited June 25, 2014 by StraightUp_OG Link to comment Share on other sites More sharing options...
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