wsimpso1

An approach used by some folks in High Power is to "house break" your rifle so that the empties get tossed at about 2 o'clock. It is a process of tuning the ejector, and I have done it on a bunch of rifles (M-1's as well as AR15's). It is nice not just for lefties, but for those of us that reload our cases - it prevents many dings that shorten case life and it allows us to recover more cases because they neither go so far nor are scattered so widely. The AR15 (and most battle rifles) has way more ejector power than is normally needed, mostly because they were concerned about maintaining reliability when dirty, fouled, etc. Since the guns for our game are kept cleaner than they would be in battle, we can tune things a little without any loss of reliability. My serious tactical rifle does have standard springs in it... I housebreak my target guns by making sure that the rifle is broken in and working correctly. Tuning the ejector of a rifle that is still rough and scratchy is wasting time. Drop the ejector and remove a coil from the ejector spring. I use a parting wheel on a Dremel tool, and break the edges and corners on the spring while I have it out. Dykes and a stone work too. I also polish the working face of the ejector, shortening it very little, and break any sharp corners on the ejector and tunnel in the bolt while I am at it. This cuts down on brass shavings fouling the extractor and ejector. We are just taking the sharp hooks off. Reassemble and test fire. The stock ejector throws cases up and out at 4 or 5 o'clock, while this should swing the ejection to 3 o'clock or further forward. If removing one coil still tosses them aft, take another coil and test again. Oh, it never hurts to have some more ejector springs in case you take off too much on the first spring. And if the idea of messing with the ejector bothers you, by all means, just mount a deflector. Do us a favor - report back on whatever you end up doing so we can learn... Good Luck. Billski

Did anybody else read the pages that Wap wap is pointing us at? This is not what I would call a high example of engineering arts. I can not let this "analysis" lie unanswered, simply because other people who might read this might also think that this is an engineering document that is correct and covers the topic of recoil correctly. First off, the stream of consciousness style of writing makes reading and interpreting it difficult, but not impossible. The lack of organization and punctuation may benefit writer in that it confuses the reader, but most of us who have a well done description of a topic would prefer that our writing be understood. Aside from the document being difficult to read, is the physics correct? Sometimes yes, but in many important places, the physics and underlying arguments are not correct… So, let's check out the issues. I will cover them in the order that they appear. The usual way of capturing the pressure curve of a firearm is to place pressure transducer in the barrel, either at the chamber and reading through the case wall, or in the barrel just forward of the throat. Both work well. In modern firearms, placing of pressure sensors further down the barrel do not demonstrate significant differences in pressure from the breach mounted one. They do serve to tell you of the bullet's passage at each point, but this has proven unnecessary because the bullet passage at the muzzle shows a distinct change in pressure that allows you to calibrate your calculations of drag. If all that you want to know is the average of soemthing, people educated in statistics will tell you a minimum of eight samples is needed. Likewise, if you want to know something about the variability and distribution of something, 33 is the statistician's minimum number. This is because we have an unbiased estimator of variation called the standard deviation, and it pretty much quits changing after the sample size reaches 33. 100 samples is overkill and produces little information that 33 does not. The author suggests a number of methods for calculating or modeling pressure data. With real data, who needs a math model? The author then discusses how pressure alone does not describe the ability of the cartridge to do work, and the author is correct, but the simplest method of describing why is not covered. In reality, the area under the Pressure-Time curve is the impulse applied to both the ejecta and the gun while the ejecta is still in the gun. The friction of the ejecta on the bore is frequently neglected due to its being small compared to the other forces, but could be included in a rigorous analysis. Where friction is included, the size of the friction estimate is checked by integrating the pressure*area – drag curve over time once to get bullet travel and checking that travel is correct. The author asserts that the gas impulse exerts its greatest force when the base of the bullet is flush with the opening of the port or brake. I wonder how the author gets that. The forces driving the bullet are simply the gas pressure applied to the area of the bullet's diameter, and this is at its highest when pressure is highest, when it is back near the breech. Now if the author is discussing the impulse of gas leaving the barrel and impinging upon the muzzle brake, the author appears to have missed the purpose of such devices. Let's get some concepts squared away. First, the powder gas of most guns is capable of traveling much faster down the bore than the ejecta is moving when it leaves the bore. If it is going slower than the ejecta , it is no longer pushing the ejecta to higher speeds, and most guns will shove their ejecta to higher speeds if you use a longer barrel. It is possible to have a barrel so long that the powder pressure falls below the bullet drag and see velocities dropping, but that is rare. 22 LR subsonic match ammo will start slowing down after it travels 16" or so in the barrel, and has a very small report, but this is a rare case. Where we have a big report, the gases are capable of going much faster than the ejecta. Second, momentum is conserved through physical interactions. Momentum of a moving object can be calculated in several ways. m*v and F*t are common versions, both resulting in units of force times units of time, lb-sec or N-s (Newton-seconds). In guns, the gun and ejecta mass have equal and opposite momentum. With friction small enough, a force applied for a certain time will accelerate a mass to a certain velocity. It really is that simple, and an English nobleman named Newton described this stuff pretty well a long time ago. Likewise, if you have several forces, each applied for small times, and you add them up, you can calculate the velocities at the end of each of the times. Extend this a bit and it becomes integral calculus, also invented by that Newton, and coincidentally, by Liebnitz the same summer. They were both working on ballistics too… So, with the bullet at the muzzle at a certain velocity, we can multiply its mass by its velocity and know what impulse was applied to it, and thus to the gun in the opposite direction. And the mass of the gunpowder has been transformed to gas, with it expanding and traveling at different velocities down the bore and driving the bullet to accelerate. If we take the mass of the powder and multiply it by one half the muzzle velocity of the bullet, we will describe the impulse applied to accelerate the gases and likewise applied to the gun in the opposite direction. This is the state of things with the bullet at the muzzle, but still keeping the gun gas inside the barrel. Once the buller leaves the bore the gun gases accelerate to whatever velocity they can, adding their impulse to the gun. Anyway, the author states that the gas impulse is greatest when the bullet is flush with the opening in the brake… Given that we now know that the impulse is the change in direction of the gas flow applied to the brake, the position of the bullet is not terribly important… What matters is that the gasses are being redirected by the baffles, and the resulting impulse on the baffle is forward, opposite all of those other unavoidable impulses, subtracting from the total impulse accelerating the gun towards you. The author cites that the gases are leaving the gun at the same velocity as the ejecta leaves, in the case of 223 Rem 3300 ft/s. I doubt it. You get a big muzzle report with 223 Rem, and longer barrels produce higher muzzle velocities. I suspect that the local speed of sound at the muzzle is quite a bit above muzzle velocity. the author does appear to have the rest of the physics right on AR15 operation – the reason for the exceptional accuracy of the AR15 is because the bolt and carrier are left alone by gun gas until after the bullet has flow free. Other gas operated guns with pushrods and the like have all sorts of gas system and barrel vibrations disturbing the barrel before the bullet is free. Part of the accurizing process for these guns is figuring out how to minimize the disturbances. The author suggests that a muzzle device for reduction of recoil is not a brake, but that it could easily be a break… Merriam Webster's Collegiate Dictionary carries its description of brake as "a device for arresting or preventing motion of a mechanism", and "something to slow down or stop movement or activity". Since the device is intended to reduce rearward motion of the barrel, it would seem to me that brake is correct. The author even goes so far as to ask what is braked. Come on now, the gun is accelerated aft by normal unavoidable gun forces, and then it is slowed some by the brake… In fairness, break is also described with some 34 examples starting with violently parting or destruction, violation, disruption, disclosure of bad news, and so on. While one could describe the redirection and separation of propellant gases to reduce barrel motion in some of these ways, it does seem to me that "brake" fits better, and is a less complicated application of the word to what its job is. Break really is the "wrong word" here. After this our author starts talking about first, second, and third moments… I have three engineering degrees from one of the better engineering schools in the world, two of them in mechanical engineering and a bunch of Physics and Calculus, and I have never heard force, acceleration, velocity, and distance described this way before, so I had to interpret a little. I believe that our author is saying that the total recoil impulse is less important than the free recoil velocity, and I think that we all agree that a heavier gun generally hurts less than a lighter one firing the same ammo. Work out the m*v of the ejecta, the powder, and the gases out the muzzle and that all equals the m*v of the gun coming back at you. More m on the gun, less v to have to stop on your shoulder. We just proved the obvious... Then, our author implies that we do not get rocket engine effects from our gun. First the author describes rocket thrust as force in N*s*s. Sorry, it does not work that way. Force is force, and force units are pounds or Newtons. Just go visit http://www.estesrockets.com/Engine_Facts1062.html and look. They cite thrust in Newtons, and oh, there it is rocket impulse in the same units we had earlier of N-s. The way that rockets and jets work is that mass is ejected at a velocity. Same as we have in a gun. That fact that our gun neither has an efficient nozzle nor does it have high fuel/payload ratio does not mean that it is not a rocket, it just means that it is a poor rocket. Since it is not meant to be a good rocket, I do not get bummed out about it. Our author goes on to cite that the powder to ejecta mass ratios of handguns and shotguns is lower than with a rifle. This does truthfully indicate how much you can do with a brake relative to the ejecta. So we can not do as much with a shotgun. This does not mean that we can not do anything useful with it, just that we can not do as much as say with a rifle. The author also cites that brakes and other compensators are not used on 40mm AA guns, 16 in deck cannons, and 105 howitzers. Sometimes true, sometimes not. You have to understand that if you fire a 120 mm smoothbore gun on an M1 tank with a brake on it, the blast will not only knock over anybody standing in their station, it will damage radio antennas, and may set off reactive armor. Some armored vehicle guns do use a substantial muzzle brake, but most do not. First off, all of these guns are in recoiling mounts to greatly reduce the forces applied to ground or vessel. In the case of artillery, you do want the guns spades to stay put so that all of the rounds in a barrage will go where you intend. If the recoiling mechanism is not used, the spades would have to be much bigger to keep the gun from shifting around on every shot. Similar mechanisms allow less heavy duty mountings of shipboard guns of many types. Next issue with big guns is that the ground, ship's hull, etc, does not really care about exactly how much force is applied to it as long as we stay below the strength of the parts. And the recuperators are designed to keep the forces to a certain level. Yeah fatigue is in there, too, but that is the essence. But us silly humans, we care about things like how hard it pushes and how fast it recovers from recoil, and we are not linear sensors. If the recoil is just above our limit of where we are comfortable, it bothers us. If it is 10% lower, we do not hurt 10% less, it becomes below our comfort level and is just fine with us. Likewise, if it speeds up recovery by a few percent, it can take recovery inside our ability to notice it, and it becomes what feels like instantaneous to us… We are not machines, and thus we have different requirements. So, we have found out that our author has his physics more than a little off kilter. So what, you say? I say, that if your model starts off out of shape, you can not count on where it will take you. Garbage In, Garbage Out. But let's follow him through. The author then gives some hypothetical pressure info, which is a little low on the pressures down barrel, but close enough for demonstration. The author calculates the force on the bullet and plots it, and cites that rockets have different shaped curves than this. So what? As I said above, guns are not good rockets, just that we get some of the same types of effects. The author then attempts to calculate forces at several places along the barrel, and the author ends up with units of kg^2/s^2*ft/lb?!? I have no idea. Force is pounds or is kg*m/s^2 or N. This mixture of metric and English units looks like nothing that I am accustomed to. Perhaps he was attempting to avoid converting back and forth between m/s and ft/s, but this sort of mixing usually just creates mistakes… Then the author cites work done in accelerating the bullet to velocity as the integral of force through a distance. Good. This is also equal to ½*m*v^2, which the author solves for v and calculates velocity of the bullet as it travels down the barrel. OK, the author does know how to do some of the math – his numbers are pretty good, but I still do not get his mixed units… The author then describes how the bullet's acceleration sags while the pressure behind the bullet drops, and how this means that less energy is also available to make the brake work. True, but that does not mean that nothing useful can come from the gas left at the muzzle. As those of us who use them can attest. The author also cites that the steeper the velocity and kinetic energy (work) curves, the sharper the recoil. What does the author mean by that? The steeper the curves, the greater the forces applied to the gun by the powder gases. Now we know that the greater the forces, the more the gun is accelerated towards us and the more velocity the gun has that we will have to stop… true, and if that is what he means by sharper, I have to agree. Then the author plots kinetic energy versus velocity, which seems pretty silly to me. Kinetic energy and velocity are intimately related by KE = ½*m*V^2. The deviation from the smooth curve appears to match the number of deviations from a smooth curve in the pressure table at the beginning… GIGO again. And nowhere does he calculate recoil impulse from driving the bullet and gases to the muzzle, the recoil impulse of the gases accelerating out of the muzzle, nor the impulse from redirecting the gases out the brake… Which would seem to me to be the object of all of these mathematical gyrations. How much recoil comes from the bullet, the gas, and how much can the brake do? The author not only does not do the calculation, he does not even talk about how to do that part of the calculation. So let's talk about that a little. When the bullet is at the muzzle, the gases are still under some pretty significant pressures and temperatures, even if they are down to "only" 4000 psi and 1500 F. When the bullet pops loose, the pressure behind the gases will accelerate out around the bullet. The pressures are high enough to cause incredible acceleration, but by some interesting behavior described well in thermodynamics, these gases can not flow faster than the local speed of sound except in some very specific circumstances. Rocket motor and jet engine nozzles actually exploit this to obtain gases at speeds greater than sound… The local speed of sound in a gas is a function of molecular weight of the gases and is very high at high temperatures and diminishes as the gases expand and cool (adiabatically). Even at the muzzle, the local speed of sound exceeds the ejecta velocity in most guns, as is obvious in high speed photographs of the bullet with glowing gases ahead of it for some distance… So, how much impulse is generated at the muzzle? Well, let's go back to the math for impulse – m*v or F*t… If we have a simple muzzle, we can calculate what is going on just as the muzzle is opened. We divide the gas in the barrel up into many small packets, and we know the mass of each packet, how fast it is going, what each packet's temperature is. We can also calculate the momentum of each packet as the muzzle is uncorked. Then we expand all of the gas out of the muzzle, knowing that each packet of gas accelerates to its local sonic velocity just beyond the muzzle. So we can compute the change in momentum of each packet of gas between when the muzzle was uncorked and when the gases are all expanded out. In a simple muzzle this impulse is computed by summing up the change in momentum of the gases to give the muzzle impulse. Add a brake to the muzzle, these gases still accelerate out of the bore, but shortly after they get out of the bore they are redirected sideways or upwards by the baffles of the brake and their momentum is changed again. This impulse is primarily forward, opposite the one that has been applied so far. There may also be ports directing gasses upward to push down on the muzzle. And the impulses are always the sum of the changes in velocity times the mass of the little packets of gas. So, while I did not do the calculations, I have told you how it might be done. While agree that the brake is a device. Billski

The topic of seeing the sights lift is covered better than I can write, but I think that I can add a cross training story. I will point out that on tough targets (small or distant) I can see the sights start to rise and then they disappear for part of the slide cycle, and then they reappear as the sights head back to alignment and the target center, so I can not see the whole cycle yet, but I do get calls on my shots that reflect my results and I get early cues when the gun locks open or malfunctions. I am still working on all of this... In 1983 and 1984, I was teaching skeet and some trap at Lordship Point Gun Club (Stratford CT). We had the nice feature of Long Island Sound blending into New England haze, which was a perfect backdrop for shooting clay targets because you could see the shot cloud fairly easily. Not the wad, the cloud of shot. I taught a LOT more rounds of skeet than I ever shot... Usually I got shooters who wanted help on a particular skeet station and they would ask how much to lead a particular target, like I know where their gun shoots, how they do the lead, and how they move the gun. I would turn it around and ask them if they could see the shot cloud, and then, almost invariably, I would have to explain how they have the best seat in the house, looking straight down the rib and watching the cloud of pellets fly directly away from them. Once you can see the cloud, you do not need me to tell you how to lead a particular target... Well, they were skeptical, but I would also explain that if they are swinging the gun smoothly and looking down the rib, they will be able to see the cloud and break the target, but the hard part is that the gun goes off and many people quit paying attention when the recoil starts. Some stop or change their swing, etc. I would then have them swing on a few targets from their problem station without ammo, which would smooth their swing and take out the hitches as they broke the trigger. Then we would do ball and dummy, with me loading the gun, and them swinging and snapping, mostly with fired shells, but slipping a live one once in a while. On one of those surprises where the gun went off, their eyes would get big - "I SAW THE CLOUD!". So then I would have them fix their lead and swing on targets without ammo and a couple targets later, they would get a live round, and usually there would be smoke! And their response was marvelous... What they had to learn to do was watch the whole shot, and they were learning to do everything. Once they learned how to watch the whole shot, seeing what happened after recoil commenced became one of the coolest things to observe. Some of them quit feeling the gun go off or quit hearing it go off, some only knew about the target, the bead, and the cloud, but they all got revved up watching the shot happen. I know now that they probably needed to keep some of the awareness, but their focus had shifted to a better place... I think that this is the same change as learning to watch the sights lift. You need to be an active spectator in the process of firing the whole shot and right into the next one. It does take practice and focus to learn it. For most of us, it also means that we have to change something that we have been doing to allow us room in our routine see things. For any one of us, this might mean time doing slow aimed fire on long targets, dry fire at the range on tough targets, ball and dummy drills, or firing on a blank backstop. You somehow have to work in time to specifically to seeing the sights so that you can help yourself learn to do something different. Once you put value on seeing the whole shot, see it yourself, and learn how to do it, it gets better and works its way into the program that you run for each shot. Tuning the mental engine is the hardest part. I hope that this helps. Billski

I started with a $200 M1100 (21" modified choke deer barrel), added a choate mag tube, a ghost ring rear sight and Williams Fire front sight, DMW feed ramp and 3" shell lifter, and tuned up the feed path, and I have a smoking M1100 Limited gun. My speed is held only by how fast I can transition between targets and handle shells. Your shotgun is a fine place to build the same shotgun. In the mean time, the shorter mag capacity only means that you will have to stuff two more shells per stage untill you can get a long enough mag on the gun. Learn the game in the meanwhile. Loading fast is what this game is about - get dummies and practice loading while walking. One per second is a good rate to work towards initially. If you have reliablity problems clean the whole gun and replace the O ring. Autoloading shotguns like to be clean. Come back to us for help... A 14.5" or 16" AR with a Miculek brake on an AR is likewise fine. If 55 grain ammo fails to make Minor by a safe margin (and that is likely) just use heavier bullets. The only fly in the ointment is you will need a fast twist to make 62 grain GI bullets and any of the other (68's, 69's, etc) heavier bullets fly well - 12" and 14" twists will not stabilize them. That is not likely a problem because 12" and 14" twist AR barrels have not been made in any volume for a bunch of years. If you do have a slow twist barrel, perhaps you can handload 60's and make Minor. Anyway, Zero your rifle to shoot point of aim equals point of impact at 50 yards and you are good to go to 200 meters on plates and IPSC paper. One other point - IFF your shorty tends to choke getting spent cases out of the gun AND has fired over 200 rounds since new, in order, clean the whole bolt and carrier, replace the gas rings, polish the chamber, replace the gas tube. Notice that there is nothing in that list about drilling the gas port... You will do fine, but start lusting for a low power glass sight and longer barrel so that light bullets will make power AND make the brake work better for faster close stuff. Prepare for three gun addiction... Billski

Government manuals and part prints on non-classified objects are not patented or trademarked or copyrighted, and are available to the public by doctrine. I would start with the US government websites. After all, we paid for them. Search on government websites, and if you find it, post the site back here. Perhaps someone on this site or AR15.com's build it yourself forum (hint) has the site already. Search that site too and see what pops. Back in the 1980's, the way it was supplied was by aperture card - yeah a black and white 35mm slide in a pocket on an IBM card. I imagine now it would be a .pdf file... Good luck. Billski

Norris, First, Patent drawings rarely have dimensions, much less tolerances or heat treat specifications, on them. I worked at Ilion in R&D during 1980 and 1981, and they treated all of the part and assembly drawings as closely held proprietary information. The engineers could get copies, but we were all educated on how the information on them would be very valuable to a competitive company. Back then, recievers, bolts, firing pins, trigger assemblies (but not many of the parts), etc were all made in house in part to avoid giving that information to competitors. Most product engineering outfits (I have worked in a few) try to do business that way, no matter what the product is. Yeah, we had confidentiality agreements with our vendors, but the big deal was that one slip and your competition knows how you make the parts. Billski1

Garrett, With mine in my hands, I had come up some ideas. First, and you got there first, is "do you have an loading ramp, and does it have enough free travel?". They need some travel before release, or the vibrating that they do during the firing cycle will trip the release or never let the action lock open. In the case of locking and then releasing, the action would start to close before the next round from the mag got into position, and probably jam up the works. In the case of never locking open, you might not release a shell from the magazine at all and get exactly the failure you have. The solution in either case is to adjust the Easyloader to give more free travel and make sure that the leaf spring is indeed in place... Second issue that might be getting you is the intercepter latch. If after getting the Easyloader working cleanly and you still get a failure to feed a round from the magazine, leave the action closed, roll the gun over and look at the magazine. If the ammo and gun are working ok here, the next round should be resting against the feed latch (the spring one that is staked in). If instead it is forward of the intercepter latch (the pivoting one), something has to be chased down there. So, check that the latches moves freely, that their springs are returning them to position. The feed latch is its own spring, while the intercepter has a torsion wound coil spring that should hold it out of the way except when the trigger has been pulled. Also check that the the link that moves the intercepter latch (in the trigger group) is moving freely with hammer release and returns when the hammer is cocked. Does the intercepter latch look OK, or has it been damaged or over relieved to allow easy feeding? You can check the intercepter latch without firing (dummy shells please) by closing the action and pull the trigger. This should rotate the latch into the feed path of the second shell in the mag, and be forward of the rim on the first one allowing it to feed. If you can easily push a round past the intercepter latch and get it caught on the other side, let's hope that a new intercepter latch fixes it, because putting material back on the inside of the mag tube and reciever is hard to do. Report back, OK, this is getting interesting. Any other comments out there? Billski

Oops. Missouri is to far away for me to look it over for you. Billski.

Geez Garrett, you got an odd one. Most of us would be happy with a gun that shoots light loads well, but we both know that this is weird and is likely to lead to a less benign failure. The cycle looks like this: Hammer falls and engages intercepter latch forward of next round (to intercept the second round, preventing feeding two); The gun fires, gas system operates and drives action bars rearward; The actions bars have a cam surface that opens the feed latch and allows the first shell to be driven past the latch and onto the carrier; The action bars finish traveling back and the gun locks open; The shell travels back and hits the carrier latch; The carrier latch frees the action bars to be driven closed. So the problem becomes that when you have heavy loads, somehow no shell gets released, but if everything else is working OK, the bolt should not close without a round being released because the new round is what hits the latch to allow it to close. Either the carrier latch is not catching the carrier (and the gun closes again immediately) or something else is tripping the carrier latch. It sounds like you have two things wrong at the same time, and I know that while it is possible, it is not likely... Does your action lock open when shot empty with a standard load? With a heavy load? When operated manually? When it does this next time, do not open the gun, but (being mindful of your muzzle) roll the gun upside down and see if the next shell up is sitting against the shell latch the way it would be when loaded, or if it is hung up somewhere else, like on the intercepter latch or some feature on the mouth of the mag tube and reciever... If it is on the shell latch, try a new mag spring. Cheap fix if it works. If it is hung up on the intercepter latch, boy, I don't know what to tell you. I do have one piece of solid advice - drop the trigger group, and make sure that the shell latch, intercepter latch, carrier latch, and carrier are all moving properly and holding things when they are supposed to. I know that you cleaned it and put it away, but I have done some unusual things when putting a gun back together, and maybe you did. Instead of abstractly imagining a M1100, I am going to get an 1100 in my hands and work my way through the problem and see if I can figure it out... I will jump on the web with my thoughts. You wouldn't happen to be in SE Michigan, would ya? Three gun shoot at Livingston Gun Club on Sunday - You could shoot the match (use my 1100) and I could look at it there. Maybe we could get some other talent to look. Billski

Hey Garrett, Sorry about my last post being off topic. If I get you right, you fire the piece, the bolt locks open, but no shell leaves the magazine? First, when was the last time you dropped the trigger group and magazine, looked at the feed and intercepter latches, and cleaned all of the junk out of there? If there is crud under the feed latch, it could be restricting movement just enough to let some rounds past and not others based on size of the rim or the amount of shell movement due to increased recoil... Next, is the magazine tube and follower clean? While a new mag spring might help, if the mechanism is slowed down by the follower and shells binding on debris, the extra fore and aft movement of the shells in the mag with heavy load recoil could get things out of time. Does your follower run smoothly in the mag tube? Again, the shell movement will be greater with heavier loads and this could get you. I have seen bent mag tubes that hang the follower... While you are cleaning check that the feed latch (long spring steel shell latch) is staked in place. If loose, get it staked (two minute job for a gun shop with the staking tool). Also clean and check the intercepter latch, which is opposite the feedlatch. These latches are best cleaned with spray solvent and then oil. Make sure that they run smoothly. Good luck. Billski

I hate to hear about M1100's not working. I worked at Ilion for a while... If your M1100 is not feeding shells from the mag, it is time for a new mag spring. If your M1100 is feeding shells from the mag, but not tripping the bolt to close it, you might need a new mag spring, but more likely you either need to install a 3" Carrier Assembly or tune the carrier for snagging the shell. Both topics are talked about in Pat Sweeny's book. The heavy load - shell on the carrier malfunction is most likely fixed with a 3" Carrier. The carrier with the little latch built in was developed for selective fire military shotguns and and also works great on heavier loads. I don't remember exactly why it makes a difference, but it does, and should be on all action shotguns. If I can remember, I will find out and add it to this thread. The position of the carrier and its tabs is sensitive to the stack up of part dimensions in the gun, and can put a tab into interference with shell as it comes aft, sucking up the energy that is supposed to open the carrier latch. Sweeny detailed how to check these out and fix them too. I will read that section again and see if there is something to help you. More later. Billski

There was a thread a while back that talked about this. If you take too much recoil out of your Benelli, it won't work. The thread (I had found it when I searched under this forum under "comp") covered the issue of Open Benelli's with comps being heavily modified, and needing heavier loads to make work, so it may not be a net gain to comp them. Billski

Jake, You are wiser than your years... That was why Benny pointed us at just using 1.5x. Scopes work well at making the target and sighting reference appear on the same visual plane, but most short range scopes set for 1.5x have a reticle that pretty well hides those eight inch plates at 300 yards. 8 inch plate at 300 yards is roughly 8/3 = 2 2/3 minutes, which is smaller than the 4 minute dot on many rifle dot sights and on the diamond reticle on my Simmons. Once that happens, how are we supposed to know where our hold is? Making the target bigger gives you a chance. Now that I am saying this, I am wondering if my Simmons enlarges the target and leaves the reticle looking the same so that this would work... Anyway, all of our three gun is at 100 yards and less in Michigan, so this only matters when I go on the road. Billski

Thanks. I am glad that you guys like the explanations. Not that it has much influence on knocking down targets, but it does explain why some of the things we do work and why some other things do not. If you have other gun op details that you want explaned, let me know. I *might* be able to help. And I promise to keep the sarcasm small. Billski

Wap wap, I did some of these calculations as part of being a gun and ammo engineer. Now I do other work on vibration isolation as automotive engineer. I know something about moving parts, spring loads, damping, etc. If the computer model accurately represents what we know from experience, it might be a good model. If it does not represent what we know, it is a poor model. And if it neglects to include correctly the physical reality that we do know and describe, it should be discarded or modified to include more of the real world. Let's talk about what we know. Assume a locked breach gas op shotgun. Guns work with short intense impulses and Newton's Laws. While the ejecta is in the barrel, an expanding "bottle" of gas keeps pressure on the ejecta, acclerating it toward the muzzle. The total momentum change imparted to the ejecta plus the momentum change imparted to gas is also imparted to the gun structure. The gas operation system has taken a small amount of gas during this process. The acceleration the gun experiences is F= m*a = P*A. m is the ridgid body portion of the gun, a is accleration, P is pressure on the base of the ejecta, and A is the area of the ejecta's base. The g's vary though out the the firing cycle based upon the pressure at that moment... G's are not constant during this process. When the ejecta leaves the barrel, the "bottle" of expanding gas accelerates towards its local speed of sound, which generally exceeds the muzzle velocity of the ejecta, sometimes by many times. During this interval, the front of the propellant gas cloud will generally pass the ejecta, and then slow down. It slows because it is expanding, its temperature is dropping adiabatically, its local speed of sound falls with it, and it can not expand at a speed greater than its local speed of sound. The momentum imparted to the gun is due to the change in velocity of the gas during expansion outside of the gun. This is how rocket engines work, only rocket engines have nozzle shaped to coax the flow in supersonic expansion, and thus get even more energy from the flow. The acceleration that the rigid body portion of the gun sees is again due to the thrust from the gun gas leaving the muzzle, and reduces as the gases drain out of the muzzle. So, the gun is accelerated with one pulse from powder pressure moving the ejecta one way and the gun the other. Then there is a second pulse as the muzzle is uncorked and the gun gas acclerates out of the barrel. This all happens in a few milliseconds, the travel is puny, but the velocities are getting up there, whether you have shouldered it or are holding it lightly. That is why we compute free recoil energy and free recoil velocity - the recoil that we must deal with is largely a matter of rigid gun mass. Light guns kick harder because they are going faster when they run into us. Hold the gun as tight as you want, it is still pretty close to free recoil during the firing cycle. When we add in a gas system, part of the mechanism starts rearward immediately when the gas is applied. In fact, we have to accelerate the action bars and slide (or carrier or op rod) to sufficient velocity and store sufficient kinetic energy during this time to operate the whole cycle. And we do. But we also have to try to open the gun after sufficient gas has drained from the barrel to allow this to occur. We do this with free travel that all of these systems have. So we accelerate another mass rearward towards the end of the firing cycle, which can help out in recoil by applying forces forward. The action bars and slide are by the way leaning on their action spring during the travel aft, imposing another force rearward, but the action spring forces are puny compared to the forces that drive the action. Gas ops help one more way - the gas in the barrel starts being drained off at the gas port once the piston has moved a little bit, speeding the drainage from the barrel and reducing the impulse applied to the muzzle, but this effect is pretty small - the gas ports are small, and the gas can go no faster than the local speed of sound in the gas there, so things are pretty restricted. We feel all of this in the difference between pumps and gas op semi-autos. Now these mid barrel brakes are an extra big drain on the gas in the barrel and well as applying a forward impulse to the barrel. Now some other factors do come into play. Ammo in the mag tube has a spring between its mass and the rigid body part of the gun. Once the gun is accelerating aft, the rounds push on the gun through the mag spring, and the ammo imposed forces working to reduce recoil can be no higher than the spring force, which is generally much smaller than the firing forces. If you have a spring that really does crunch down solid just as the last round goes home, the ammo would add fully add its mass to the gun for the first shot. If the spring really does crunch down another say 0.060" under a 200 pound push, the ammo will float during the most important part of the cycle. So, the amount of ammo in the mag will not generally play much of a role in felt recoil. Gun weight will play a big role. Gas systems will help. And ported barrels will make significant reductions in recoil, resulting in huge differences in shooter perception of recoil.

Plates at 300 AND at point blank? Tough stage. I tried shooting plates at 200 with 1.5x and did not like it, but with practice, I bet that you could do it. I am jealous that you have a place where you can do plates at those distances. Our clubs that shoot tactical rifle all go 100 yards and less, and 1.5x works fine at those distances. If you see that sort of thing very often, I would also think about the JP Short Range on your forend, then you can dial whatever magnification you want for distance and use the hoser sight for the shorties and while moving. Some folks can shoot 5x with both eyes open on close targets, but I can not. Benny's suggestion of adjusting during movement is something to practice too. It sounds like experimentation is in order. So much to learn... Anybody else working on this? Billski

A lot of the mounts shown so far put the scope way too far back for me - I would end up with an eyesocket full of ocular lens. This scope needs some 3" of eye relief and that lets you do fast transitions... I went with a GG&G Scout Rail and a set of medium hieght rings so that I can get it high enough and far enough forward to work in prone and kneeling positions. Works great, is sturdy, and I can attach folding sights should the scope have to come off. Billski

Last I knew , Simmons Scopes are neither the low cost end of the Japanese makers (which does tend to be shakey on quality) nor Chinese (low quality AND money to a communist regime) but from the Phillipine Islands, which is an English speaking and primarily Christian country that is trying to build both its reputation and economy, sort of like Japan in the 60's. Everything I have seen from them has been pretty high quality, and I mind sending my money there a whole lot less than to China. Billski

Here are some for SE Michigan that you did not have : 1st Sat IDPA Linden Sportsmen's Club 2nd Sat IDPA Livingston Sports and Conservation Club 2nd Sun Three Gun Livingston Gun Club 3rd Sun USPSA Detroit Sportsmen's Congress 4th Sat IDPA Capital City Rifle Club 4th Sun USPSA Livingston Gun Club Also on 2nd Sun, Chief Okemos is having USPSA/IPSC pistol sometimes and three gun on others. That means that a three gun shooter has to choose between them and Livingston Gun Club on those days - only 40 minutes apart - what a shame. Billski

George, You could do that experiment, but I can tell you up front that your result is likely to mislead you. If your mag spring is really bound up solid, the ammo will add to the weight of the gun in recoil. But you are unlikely to ever get it that bound up. Lets get the magnitude of the forces understood here. I answered before without having numbers but knowing that they were big. I went and calculated some example ones. High school physics will give it all to you. If your bird shot shells make a max of 17000 psi, eight pound gun is accelerating at you at over 600 g at peak, and is still accelerating towards you at 100 g when the ejecta nears the muzzle. Then you get another brief pulse of hundreds of g's when the bore is uncorked. Now during all of this accelerating, the travel moving your shoulder is still miniscule. Mostly, the gun gets moving, the shot leaves the barrel, and then the gun gets stopped by pushing you around. If the bird shot cartridges were to recoil with the gun, the spring would have to come up with over 60 pounds (yes, pounds) per bird shot cartidge, and would still be around 10 pounds as the ejecta approaches the muzzle. A stack of eight rounds would require a spring force of over 480 pounds to prevent floating completely and 80 pounds would still allow it to float over almost all of the firing cycle. Anything less than 80 pounds and the rounds will be floating on the spring during the entire firing period and participate in recoil reduction to the level of the spring force only while floating. Now, consider a fixed machine stand, bolted to a concrete slab and the gun does not budge during firing - under these circumstances, the gun and the stand will experience the forces that the powder applies to the ejecta - ugh, thousands of pounds. That is why aviation machine guns are mounted in recoiling mounts and artillery, tank guns, naval guns, etc all have long stroke hydraulic recuperators. And they all still require substantial spades on ground based equipment. We humans are shoved by a shotgun, and it really recoils pretty freely for the first few milliseconds when all of this interesting stuff is going on. The forces in gun firing are very big, but also very brief, or we would not be able to have all of this fun shooting and thinking about it. Anyway, having a mag spring bound up to the point of preventing float in the mag tube is tough to fathom. Now for the skeptics who really want to test this theory about the ammo floating, you could pull the mag spring, load the mag, and put in something (a spring or chunk of foam rubber) to hold the rounds against the front end of the tube so that the mag carries them all in recoil. Then fire it and compare it back to back with firing with an empty mag. Or you could use some clamps to attach some steel slugs to the barrel. Oh, and watch for the clamps slipping along the barrel during the tests... Billski

Miculek brake works great on my 18" rifle. Snake eyes on 7 yard aimed doubles. Bill Drills run very fast for this beginner at 15 and 25 yards. Alex's brake does look mighty tempting though. Billski

I am too new to this game to count while shooting the match. I fire plan, and know where I am going to reload, and if it is shotgun, how many rounds. If I have a miss, I count the miss and TRY to add that to my next load, but what usually happens is I end up stuffing another shell to finish. So I really work at getting hits. Planning for where and how many is also planning for the gun going empty on the last shot in this game. Now if we were training for a real fight, we would load as many as we shoot during the course. My armed citizen routine is pistol and carbine. Let's not even talk about the shotgun... I am paying attention to counting shots as I learn and get trigger time, and I am hoping that my awareness, including rounds remaining, improves, but I am not counting on it. Here's why: In High Power, the course of fire is always the same, and we either have two clips of five rounds (Match Rifle) or two and eight (Service Rifle), and after five fairly serious years, I was still not sure when the rifle would go empty. Goog thing the Service Rifle tells you by locking open. I have shot lots of dry rounds with the Bolt Gun. I am not holding out hope for knowing how many are in the gun in a game where the course of fire varies as much as it does here. Good luck. Billski

Think about how the shotgun mag is constructed, and you will have an idea why the full mag does not feel different from an empty one... The rounds are held aft in the mag tube by the mag spring. When the gun recoils, the ammo wants to stand still, the gun recoils, and the mag spring compresses some. So the ammo in the tube is really not resisting recoil unless the mag spring bottoms out, and by then, the recoil has already poked the shooter in the shoulder. Yeah, the force from the mag spring is pushing forward on the gun, but it is puny compared to the forces in the recoil impulse. Also, we get that impulse back (in its entirety) when the stack of shells, driven by the mag spring smacks the latches. The Rem M1100 and M1187 have an intercepter latch that drops down forward of the rim of the next shell when the hammer is released. This prevents trying to feed more than one round, but also captures the first round, so it does recoil with the gun, sort of - there is clearance here too, allowing some motion and thus not showing the recoild reduction. Other semi-autos have similar features doing the same thing for both feeding and for making the ammo have little to do with recoil reduction... There is a lot of stuff going on during the firing and auto-loading cycle! Billski

First, the page you sent us to is bot working. Second, It would really be helpful of you folks would put the location for the matches in these notes. If everybody knew all about these matches, making the announcement would not have a function. Billski

Burma Shave was a shaving cream company. I know this from a magazine article in a car mag from back in my youth talking about a past advertising form. Before the interstate highways increased our highway speeds, they had these advertisements that were witty little poems in several signs at a nice spacing, always ending in Burma Shave. Billski