Recoil / Muzzle Flip

[woolfam]

I was watching Ruger's promo video of their new pistol (as seen here) and noticed the varying degrees of apparent recoil experienced by the shooters.

The recoil experienced by one of the shooters, at the beginning of the video, causes enough muzzle-flip to raise the end of the barrel 6-8". A couple of the shooters seem to experience relatively little recoil / muzzle flip.

Assuming that they are all shooting a 9mm round, I figure the three recoil-affecting-factors involved are:

1) energy of the round being fired

2) the technique / grip being utilized by the shooter, and

3) the hand and arm strength of the shooter.

Firing commercial ammo out of my Ruger P93, I tend to have as much muzzle-flip as does the shooter at the beginning of the video. I'm not new to pistol shooting - been doing so for 10-12 years.

Are the shooters in the video with relatively little recoil probably using very low pressure rounds, or do they just have much better technique than do I, or are they just that much stronger?

 

[Mad Magyar]

Are the shooters in the video with relatively little recoil probably using very low pressure rounds, or do they just have much better technique than do I, or are they just that much stronger?

BINGO! Add #4 to your list:
Customized pistols to reduce muzzle flip: porting/compensators, custom barrels, added wghts, etc....
However, to their credit many of these competitors when preparing for an event might be shooting a 1,000 rds a week. Technique is perfected through practice.

 

[Zak Smith]

5. Stronger recoil springs in semi-auto pistols generally increase muzzle flip; weaker recoil springs generally reduce muzzle flip.

It's mostly technique though.

 

[GunNut]

Proper technique is probably the main reason, between the different shooters.

 

[makarovnik]

There is a difference between muzzle flip and recoil. I don't mind muzzle flip but recoil can be painful. Stronger recoil springs reduce recoil.

 

[nwilliams]

IMO better technique accounts for more control of both muzzle flip and recoil.

Controlling recoil is possible with practice and proper training. Especially in rapid fire its easy to let the recoil of the gun take over, this is where lots of practice pays off.

Strenght really isn't a the key, you can watch professional woman shooters who may not be as strong as the males but can control recoil and muzzel flip just as well and sometimes better depending on the shooter.

 

[DawgFvr]

Porting = 70% less muzzle flip at a 100 ft per second loss of velocity. The hotter the round...the better the porting works.

 

[1911Tuner]

Stronger recoil springs reduce recoil

A common misconception. Stronger recoil springs slightly reduce slide to frame impact, but increase felt recoil through the secondary recoil impulse.
Since it's an action/reaction event, whatever force is imposed in one direction is automatically and instantly imposed in the opposite direction.

When the spring compresses, it resists the slide's rearward movement, trying to return it to its forward position. While it's resisting...since springs work in both directions...it also pushes rearward on the frame with equal force.
So...If the spring's compressed strength is 16 pounds, it's pushing slide and frame at the same time with 16 pounds of force. If the spring's compressed strength is 20 pounds...it's pushing on slide and frame with 20 pounds of force.

Clear as mud...Right?

 

[RyanM]

Another way of putting it, recoil can be divided into two elements. Shove, and Snap.

Shove is primarily determined by the rearward velocity of the gun multiplied by the amount of time the recoil acts on your hands. Snap is the recoil velocity of the gun divided by the amount of time the recoil acts on your hands. If you decrease one with spring weights, you must necessarily increase the other. Other things can change them too, however. Attaching weight to your gun decreases both (by decreasing velocity). Using a recoil buffer or padded grip will decrease snap without affecting shove (because it only acts for a very short amount of time, but it's the point in time that's the most significant).

A revolver or single shot pistol would be the baseline. The amount of time the recoil acts on your hands is fixed, for a given load. Recoil time = time the bullet is in the barrel. Can't change that without changing your ammo.

A straight blowback pistol with light springs would be the minimum of shove, maximum snap. As the slide recoils, the only recoil transferred to your hands is whatever makes it through the spring, which will be a relatively small amount of the total recoil impulse. Then the slide reaches the limit of its travel and whack, you get all the rest of the recoil all at once. The recoil impulse is delayed by the slide movement compared to a revolver (the bullet is long gone by the time it's all the way back), but that "whack" transfers recoil a lot faster than the bullet moving down the barrel.

A recoil action pistol with heavy springs would have the least snap, but the most shove. Like the blowback pistol, you get some percentage of recoil through the spring. However, you also get a fairly big piece of it when the barrel stops, sort of a small "whack." Then you get the big slide whack at the end. The barrel is usually rather light compared to the slide, but that little whack makes a pretty big difference in shooting comfort.

 

[1911Tuner]

The barrel is usually rather light compared to the slide, but that little whack makes a pretty big difference in shooting comfort.

In most tilt-barrel recoil operated pistols, the barrel drops and stops at about a quarter-inch of slide travel...so ya probably won't notice the barrel whack, since it happens about the time that the spring is startin' to get a head of steam.

 

[RyanM]

You won't notice the whack itself, but it does make a difference. The bullet is all the way out before the barrel stops, so 100% of the recoil impulse has been absorbed by the recoiling components, and both are moving at the same speed, and will also be close to their highest speed relative to the frame. Let's see, Glock 23 barrel is 3.5 ounces, slide is 13.25. 180 gr at 950 fps... 23.3 fps max slide/barrel velocity. So you get about 0.158 sg-ft/sec of impulse almost immediately, some unknown percentage of 0.600 sg-ft/sec through the spring, and the rest of it at the end of slide travel. The rest of the physics for that are way too complex for me, but it does make a noticable difference. Firing a Colt Mustang is a totally different experience from firing a Walther PPK! I'm guessing Glock and Hi-Point are similarly different, but I've never fired a Hi-Point.

 

[1911Tuner]

No disagreein', Ryan. In fact, the barrel stoppin' against the frame is probably half of the total felt recoil at that point in the slide's travel and spring compression. Just meant that you wouldn't be able to differtiate between the two. They come too close together.

And...the bullet is long gone by the time the barrel stops. It exits at about .100 inch of slide/barrel travel.

 

[The Annoyed Man]

I've got a question for you more knowledgeable guys...

I've must made my first foray into .40 S&W ownership. What I've noticed is that the round seems more "flippy" than the .45 ACP I've been used to shooting. However, the two pistols are not otherwise identical. One is a stainless steel Sig 1911 with a 4.25" barrel and shooting a 230 gr bullet, and the other is a polymer framed HK USP Compact with a 3.5" barrel and shooting a 180 gr bullet.

Given those differences, is the .40 S&W inherently "flippier" than the .45 ACP, or is the subjective difference I am feeling probably related more to the differences between the two pistols and the bullet weights?

 

[Zak Smith]

The USP has a much lighter frame, while the 1911 has a heavy steel frame. 45ACP is a lower-pressure round with a slower muzzle velocity, while the 40SW operates at higher pressure and muzzle velocity. The shorter barrel of the USP Compact (3.5" vs. 5") will also contribute to flip.

When shooting 10mm vs. 45ACP through the same Glock (model 21) by swapping "uppers" with ammunition of about the same power factor (momentum), the 10mm is snappier and recoil finishes faster.

-z

 

[Maddock]

Zak Smith: 10mm vs. 45ACP through the same Glock (model 21) by swapping "uppers" with ammunition of about the same power factor (momentum), the 10mm is snappier and recoil finishes faster.

I've noted the same on the 1911 platform and with S&W N frames (I know revolvers are a different animal entirely). I wonder how much gas pressure at the muzzle affects this?

 

[The Annoyed Man]

Zak, thanks for the answer. I'm still a little perplexed, because A) the HK feels a little muzzle heavy in the hand which I would think would act against muzzle flip, while the 1911 is perfectly balanced; and B) even when I fire Corbon +P 185 grainers at much higher velocities in the 1911, it still doesn't flip much. Also the muzzle velocity in the HK and the 1911 aren't that far apart when shooting the 230 grain .45 rounds out of the 1911.

Guns are endlessly fascinating critters.

 

[Zak Smith]

The USP Compact weighs over a half pound less than the 4.25" Sig 1911.

 

[RyanM]

Don't forget, the slide is all the way back when you get a large part of the recoil. Try locking the slide back on the USP, and see how it balances. Not front-heavy anymore.

 

[makarovnik]

All I can tell you is that I replaced my recoil spring with a stronger wolff spring and the felt recoil was greatly reduced shooting the same loads.

Especially if your pistol is a straight blowback action; much of the felt recoil is from the slide smacking against the frame. Imagine how the recoil would be if you took the spring out alltogether. It would be painful. I think it's prudent to use the strongest spring you can while still being able to have reliable extraction and ejection. This will make the pistol easier to handle, cause less damage to the frame and help keep your ejected brass from flying 20' away. My makarov used to fling brass all over the place until I put a stronger spring in. The only reason to use light springs is if you are using low power loads and your slide is not cycling properly.

 

[Zak Smith]

There is a window of recoil spring strength (actually spring "k" value) in which the pistol will operate reliably with normal ammunition. Straying too far from the center of this region, either light or heavy, will increase the malfunction rate.

 

[1911Tuner]

I wonder how much gas pressure at the muzzle affects this?

For all practical purposes...None. It's still a matter of action/reaction.

Gas and residual particulate has about the same mass as the unburned powder charge. In a .45 ACP, it would exit at roughly the speed of sound.
Let's say a thousand fps just as a rough guesstimate. The average powder charge for the cartridge weighs in at 5 grains. Just figure it as though it were a bullet of the same mass. 5 grains at 1,000 fps would generate about 1/8th the recoil impulse of a standard velocity .22 Short in a 2.5-pound gun. In other words...Nothin' you'd notice.

 

[The Annoyed Man]

Don't forget, the slide is all the way back when you get a large part of the recoil. Try locking the slide back on the USP, and see how it balances. Not front-heavy anymore.

I hadn't thought of that.

 

[1911Tuner]

Don't forget, the slide is all the way back when you get a large part of the recoil.

Ryan made an important and often overlooked point there. An autopistol's center of gravity and mass is under constant change through its cycle, so that whatever effect recoil has on the gun is multiplied by that change.

Good point, Ryan.

 

[1911Tuner]

All I can tell you is that I replaced my recoil spring with a stronger wolff spring and the felt recoil was greatly reduced shooting the same loads

Perception, m'fren. It flies in the face of physics. Specifically, the 3rd Law of Motion/Conservation of Momentum.

To wit:

"For every action, there must be an equal and opposite reaction."

If the spring is pushing forward on the slide with X ft pounds of force, it's pushing backward on the frame with X ft. pounds of force. There just ain't any way around it.

Now...the stronger spring reduces the slide to frame impact at the end of the slide's travel, and that may be where your difference lies.
There are better ways to reduce that without going to a stronger spring, and without plastic shock buffs.

 

[davepool]

The muzzle flip is all in the grip