Exactly when does a muzzle "flip"...

[GMyers]

When does muzzle flip actually occur.  Does it begin at the instant the powder begins to build significant pressure and the slide/barrel begin their motion?  Or does it occur as the bullet is leaving the barrel and the high pressure gas escapes much like a rocket motor?

Thanks for any information!

Greg

(Edited by GMyers at 9:28 pm on Aug. 20, 2001)

[DBChaffin]

I am not a physicist or anything and I can't tell you why, but I can show you something that I think that many here will be interested in.  There is a German website where they used some very high speed cameras (1000 or 2000 frames per second) to film guns firing.  The "flip" definitely seems to occur after the bullet has fully exited the barrel.  Go to http://www.kurzzeit.com/index_e.htm and click on films.  Dowload a couple and see what you think.  Anyone care to explain the physics behind it?  I am guessing something simple like Newtonian "for every action there is an equal and opposite reaction" type stuff.  The fact that a person/gun weighs much more than a bullet causes the force to be spread out over time (slower).   Anyone help here?

As an interesting side note, if you get the video of the .45 that is 2000 frames per second, watch when the shooter's eyes blink.  Very interesting stuff I think...

(Edited by DBChaffin at 11:49 pm on Aug. 20, 2001)

[Bill Schwab]

DB,

When I download those films they always show up as a Word file and then I can't open them.  How do you get them to work?  Thanks in advance.

Bill

[Jerome Poiret]

Bill,

What I did is:

Don't download the files, open them from their current location. You can then find them in cwindowstemporary internet files.

You'll need Winzip to unzip, then a player like Windows Media Players. If you want to save them, put (copy/paste) them in another file.

It worked for me, except with one that appeared to be an image (?).

Hope this help, because they are nice movies.

[ErikW]

Those films show muzzle flip occurs long, long after combustion, long after the bullet has left the barrel, likely long after the bullet has hit the target.

[benos]

Maybe it's because the combustion/bullet exiting process happens so fast, it just take the gun that long to react. Maybe "that long" isn't really all that long. Maybe kind of like - something that's very warm to the hand ain't shit to steel?

be

[BigDave]

I believe its a couple of things:

1) the cumbustion creates a vaccum (not a true one though) and the air rushing back into the barrel contributes to flip

2) the torque created by the spinning projectile relieved when it finally exits the muzzle

3) the slide (autos only) moving toward the shooter and closer to the pivot point at the wrists, there is alot of inertia to 'control'

I believe its is primarily the first two.  I don't have a revolver or like to compare it two my auto.  I know in a shotgun, the auto recoils less (especially gas operated systems like the Rem 1100/1187, vs my recoil operated Benelli M1, which would explain an overall reduction in felt recoil in the 1187 vs M1, the M1 is comperable to my 870)

I could be way off base, but its just my $.01

(Edited by BigDave at 3:31 pm on Aug. 21, 2001)

[DBChaffin]

Bill, sorry about that.  When I downloaded them my mp3 player (WinAmp) tried to run them and it can't because they aren't mp3 files.  I just open Windows Media player like Jerome said after I unzip them, uh, like Jerome said, and then open the files.  Hope you get to check them out.

[38supPat]

I think you dudes are just plain thinking too much...we're talking aout milliseconds here...although it appears to take awhile on slow mo film we all know it happens quite quick. It may take that long just to overcome the mass of the gun..It would be interesting to do some experiments with different weighted guns to see...like a major load in a fairly light gun...like the new SVI IMM gun I am getting, and a Limcat which is  extremely heavy for an Open gun. Or for that matter a stock Para vs. a long slide heavy dustcover SVI limited gun. Does the weight affect the time involved...then again does it really matter

Pat

[GMyers]

DB, thanks for the links!  Really great video of "the truth" (I have been reading The Book).

As best I can see, the muzzle does not begin it's upward travel until after the bullet has exited the barrel, however minutely.

I think this tells me, and tell me if I am wrong, that first shop accuracy has everything to do with sight awareness, grip and trigger control.  Recoil should only effect, potentially, loss of one or more of the above three.

I ask these questions because I want to understand the mechanics of firing a weapon so that I may move beyond them. Another cluttering piece of the puzzle has been removed!

To date I have shot one IDPA match as an unclassified "Novice" and won the class with a 152.65 (I know, I could use a calendar for a timer).  This weekend I will shoot my first classifier match, with a goal to SEE my way to CDP SS.

Thanks all, for your input.

GM

[BigDave]

Pat - in so far as the time and moment you, we, are shooting, it doesn't matter a bit.  

[BroadSide]

I need one of those cameras.  Anyone notice the shooter in the 2000 frames/second version closing his eyes under recoil?  I'd hate to think of all the nasty habits I'd reveal under that kind of scrutiny.

[BamBam]

I have been thinking a lot about those videos.  This stuff fascinates me... in particular the #8 and #17 (I think) showing the OPEN gun and LIMITED gun in recoil.  The personal experiences and "feel" we talk about are far more subjective (and thus less accurate) than the physics behind what is happening.  There are real forces at work so there MUST be a real singular answer.  Aren't there any physics teachers who shoot that can offer anything here??

I am only an engineer but what I see is this:

The limited gun begins  its muzzle lift when the muzzle blast occurs.  This would make sense if the force of gases exiting the muzzle pushes the gun back into the hand like a rocket engine.  The hand then begins to pivot at the wrist.  There is likely some more force added back into the hand from the slide weight moving against the resistance of the recoil spring.  Finally there is another sudden surge of muzzle lift when the slide smacks its end point of travel from suddenly stopping the weight in motion.

The Open gun video really seems to offer the added evidence for a preliminary conclusion.  In that video, there is almost no muzzle flip at all from the muzzle blast.  The compensator seems to do the perfect job of diverting the muzzle blast.  Its probably a combination of NOT going out the front and INSTEAD going out the top and sides that causes this balanced flat action.  There is no muzzle flip really at all until the slide "hits" its stopping point.  Open guns use less recoil spring so the force "during" slide recoil can be debated, but it seems clear that the slide suddenly stopping is 95% of the reason for muzzle lift with the open gun.  In that case it seems logical that a light slide with adjusted spring rates to soften the final slide hit in recoil is the best answer.  However, you then have to balance that against over-springing the slide return which would cause muzzle dip.

I did some measurements of recoil springs standard versus variable.  I found on average that in the first 1" of compression, the variable spring offers 1 lb. less force than its equally rated standardversion.  At 2" compression it is 1/2 lb. lighter, and at full compression of course both springs reach their same numerically rated maximum.  I think the answer might be springs even MORE variable in strength.  

Anyone have a friend in the production department at WOLF or IMSI ?  

It has to matter because there is one answer that is better than another.  Determining it is an advantage no matter how big or small.  I think the combined sum of our efforts here might yield that elusive answer.  Anyone?... Beuler??

[bonedaddy]

GM, good observation about recoil effecting sight alignment, trigger control, and grip.   There are other elements that can be, I guess "disturbed" is the word, by recoil.  These are calling the shot and follow-through.

     Recoil is the one thing in the cycle that just "happens".  The others, we initiate.  But any one of those other five elements gets knocked out of line because of lack of recoil management and shot placement will suffer.  

     Recoil seems kinda like the wind.   A force of nature.

[GMyers]

BD, just like the wind, I can't stop recoil but I can understand it.  Between this thread and SMoney's higher on the tree, I ~think~ I am beginning to see the light.

Just receieved a full set of various 1911 springs from Wolff today so this weekend I will put on my mad scientist hat and figure out recoil for myself.  After those questions are answered I will just shoot... until the next question comes along.

BamBam, sounds like some pretty cool analysis!  I will post here, my subjective recoil results after trying some various spring combinations.

It's all probably for not but it beats mowing the lawn!

[bountyhunter]

Muzzle flip begins at the exact instant there is any force moving forward down the barrel toward the muzzle, be it escaping gas, bullet acceleration, or both (I suspect both at the same time).  Newton's law of motion requires an equal force be directed backward to balance the force of the gas and accelerating slug.  In an auto, a significant portion of recoil energy is used up moving the slide backward loading into the slide spring. The recoil signature of an auto shows a peak at time  of discharge with a lower recoil as the slide goes back then another small bump when the slide hits the frame.  In a revolver, all the kick is delivered to the hand at the instant of firing.

[BamBam]

BH - I think you would be more correct to say that RECOIL "begins at the exact instant there is any force moving forward down the barrel toward the muzzle".   Muzzle flip is really only a by-product of recoil energy rotating around the axis of your hand holding the gun.  If recoil could be managed in such a way as to reduce muzzle-flip we would all be far happier.  Open guns control recoil with their comps.... initially.  But watching that [in]famous slow motion video I see that with Open guns the most significant element of muzzle flip occurs when the slide hits the slide stop in recoil, and the gases from the comp have finished their counterforce effect.  Its as if solving the muzzle flip problem started with the invention of compensators only to expose the next weak link in the chain.  That would have to be side mass coming to a sudden and violent stop, so it is now THE WEAKEST LINK.  Goodbye!  HA!  I think the answer would be a lighter slide and variable springs with a more exponential strength curve than those currently available.  The best feel for my open gun at full recoil is an 11 lb spring, but the best spring for return without too much muzzle-dip is a 10 lb variable.  Nothing available now does both.  Anyone have any friends at Wolf or ISMI?

far more recoil results on teh Open gun when the slide Recoil is inevitable and unavoidable.  Using our science, thoughts, and experiences we can come up with ways to reduce the subsequent effect on muzzle flip.

, be it escaping gas, bullet acceleration, or both (I suspect both at the same time).  Newton's law of motion requires an equal force be directed backward to balance the force of the gas and accelerating slug.  In an auto, a significant portion of recoil energy is used up moving the slide backward loading into the slide spring. The recoil signature of an auto shows a peak at time  of discharge with a lower recoil as the slide goes back then another small bump when the slide hits the frame.  In a revolver, all the kick is delivered to the hand at the instant of firing.

[Detlef]

(changed my mind about posting this...)

(Edited by Detlef at 11:50 am on Oct. 26, 2001)

[Nik Habicht]

Detlef,

No physics lesson today?

[Singlestack]

Rats...........

I was waiting for the Detlef physics report. I really enjoy them.

[DBChaffin]

Detlef,

     I got to read your post before you changed your mind and almost replied that I think its cool we have a physics expert here.   I enjoy them also.  

[Detlef]

I saved it. Will have to add something and make it more readable  

--D.

[bountyhunter]

Mr. BamBam:  my answer was correct.  Muzzle lift begins exactly when there is any forward energy.  Even though the slide moves rearward absorbing some (or most) of the recoil energy, there is still a recoil impulse at time of ignition directed rearward (it is smaller than a revolver of course).  The recoil impulse is directed back along the barrel about 2" above the center of the wrist resulting in a rotational force around that point.... ergo, the gun moves backward rotating on that point and the muzzle must rise.

[BamBam]

To the hunter of bounty: you are correct that the energy of launching a projectile forward will create some degree of recoil backwards, and that any recoil backwards will rotate around the pivot point where you hand holds the pistol thus creating the first moment of muzzle lift.  But here are some thoughts to explore...

1.  If a compensator sent the necessary force upward as the slide recoiled, could it eliminate muzzle flip during recoil?  Watching that famous slow motion video it appears that this works for the initial moment of firing.

2.  The recoil energy is partially absorbed (stored) by the action of moving the slide weight against the spring.  Obviously this works by your comparison to the muzzel flip of a revolver.  So what slide weight and spring combination would work best to reduce the muzzle flip aspect of recoil?  Is it light slide or heavy slide (sprung correctly) that works best?

3.  Once deciding on light slide or heavy slide for initial reduction of muzzle flip, does it make your condition better or worse when the stored energy in the moving slide is suddenly (and violently) released when the slide hits the slide stop?  

4.  BONUS QUESTION - What creates the larger component of muzzle flip... the initial recoil of launching the bullet, of the impact of the slide hitting the end of its travel?  Whichever factor is the greatest cause of muzzle flip would be the one that would give the best results when tamed.  

Watching the slow motion video it apears to me that we experience more muzzle flip as a result of the slide hitting the stop than the initial launch of the bullet.

Basically since we all know WHAT is happening, the big question becomes "What we can do to best reduce the magnitude of muzzle flip".  

[bountyhunter]

Good questions.

>>>>>>1.  If a compensator sent the necessary force upward as the slide recoiled, could it eliminate muzzle flip during recoil?  Watching that famous slow motion video it appears that this works for the initial moment of firing.

Compensators certainly do reduce muzzle lift by balancing an UP force against a DOWN force.  Usually, there is still some lift but a lot less.  But, they are noisy and spray crap back at you. I had a barrel ported and then junked it.

>>>>>2.  The recoil energy is partially absorbed (stored) by the action of moving the slide weight against the spring.  Obviously this works by your comparison to the

muzzel flip of a revolver.  So what slide weight and spring combination would work best to reduce the muzzle flip aspect of recoil?  Is it light slide or heavy slide (sprung correctly) that works best?

I haver seen published graphs of recoil impulse energy versus time after the instant of firing on autos.  There is a medium sized bump (at discharge) then a flat level of recoil energy about 1/3 as tall as the first bump (as the slide moves backward into the spring) and another medium sized bump when the slide hits the frame.  A lighter recoil spring makes the initial bump less, and the final frame impact bump more.  The best spring would balance these two.  I think the manufacturer's recommended springs come pretty close to a balance.

>>>>>3.  Once deciding on light slide or heavy slide for initial reduction of muzzle flip, does it make your condition better or worse when the stored energy in the moving slide is suddenly (and violently) released when the slide hits the slide stop?  

Answered above.

>>>>>>4.  BONUS QUESTION - What creates the larger component of muzzle flip... the initial recoil of launching the bullet, of the impact of the slide hitting the end of its travel?  Whichever factor is the greatest cause of muzzle flip would be the one that would give the best results when tamed.  

With a proper recoil spring, they are similar in magnitude but the initial bump (discharge) is usually a bit higher.  The reason is you want to minimze frame battering so a stiffer spring is better for that.

>>>>>>Watching the slow motion video it apears to me that we experience more muzzle flip as a result of the slide hitting the stop than the initial launch of the bullet.

Maybe so.  I've never seen a good slo-mo of that.  Of course, the lift at the frame bump doesn't affect shot accuracy because the bullet is LOOOONG gone by then.  It just makes the next shot take longer to sight in.

>>>>>Basically since we all know WHAT is happening, the big question becomes "What we can do to best reduce the magnitude of muzzle flip".  

A good compensator is probably the best thing (if you can stand the noise).  I'm not sure muzzle flip is all that horrible in a typical gun.  If you have adjustable sights you can "dial out" whatever lift effect you have for your personal grip strength and type of ammo.  When I change from .38special to +p in my revolver I have to crank the sights to zero in.  Autos don't have such a big change because the recoil energy is spread out more.  Just crank the sights until you are hitting the black and you're done.  It doesn't really matter where the bore is pointed.