Per the recommendation of grayguns, I installed a lighter (15 lbf) recoil spring on my P320 to reduce the muzzle dipping too much after the slide goes into battery after each shot.

I wanted to SEE the difference the lighter spring makes, so i attached a laser to the P320 and recorded the laser movement while firing the pistol. Using the video, I measured the distance the laser dipped after each shot. Indeed, there is noticeable improvement using the 15 lbf spring versus the 18 lbf factory spring.

I did the same test with my G34 gen4. What I discovered was not expected: There was no discernable difference in muzzle dip between the 13 lbf reduced power spring and the 17 lbf factory spring. This puzzled me. I had read from other Glock users that a lighter recoil spring would reduce muzzle dip; and I can FEEL a difference in the recoil impulse. But i did not see any measurable difference in muzzle dip. What's the deal?

Can any of you comment on your experiences with Glocks and reduced power recoil springs? Thanks

Kevin

I never took physics, but I would imagine that it has to do with how recoil, force and inertia affect the vertical movement of the Glock 34's longer barrel and slide as opposed to the shorter P320 barrel and slide.

There's muzzle dip? That's greater than the muzzle flip that precedes it?

quote:

Originally posted by kkina:
There's muzzle dip? That's greater than the muzzle flip that precedes it?

I looked up some "Slow motion gun firing" gifs on Google and found this one.


it best shows how suddenly, the muzzle flip is pushed forward again by the slide locking closed. I suppose that would/could push the gun down a bit, too.



in, say, a 3-shot rapid fire, do your shots tend to climb up or drop down? I'd surmise the whole need for a lighter spring is only necessary if they go down, as that forward impulse is driving your gun down for follow-up shots. (or, you're anticipating the next shot and dropping it.)

quote:

Originally posted by kkina:
There's muzzle dip? That's greater than the muzzle flip that precedes it?

You can almost seee it with the naked eye when you put a 40 recoil spring in a 9mm 226.

quote:

Originally posted by jljones:

quote:

Originally posted by kkina:
There's muzzle dip? That's greater than the muzzle flip that precedes it?

You can almost seee it with the naked eye when you put a 40 recoil spring in a 9mm 226.

Learn something new ever day.

Every time someone talks about bore axis, they say "it's physics!" To which I respond, "and those same physics are suddenly void as the slide returns to battery?"

I've found the only time I dip the muzzle is if I'm shooting .40 a lot then switch to 9.

Could also be an issue with grip. See video below starting at about 19:30. There is also some slow motion videos shortly thereafter.

I think we are confusing a couple of things here. Grip isn't going to fix the issue of the gun being oversprung. Frankly, I don't know why you would want it to. Simply changing out the spring to take out the dip when the slide closes seems to be the wiser choice.

The issue the OP is talking about is not a matter of technique. It is a matter of the gun being so oversprung (usually to facilitate heavier recoiling loads) that at the end of the stroke when the slide is closing, the muzzle dips slightly.

Thank you, jljones, for clarifying.

The mystery remains why I did not see improvement with the G34, and contrary to others' experiences.

Kevin

I'd have to guess that the gun was way too oversprung to begin with. Remember that Glock severely dicked with recoil springs and everything else to try to solve the light mystery on the .40s, and the BTF issues on the 9. The recoil springs may be way too much, and by dropping just slightly, you didn't take enough poundage off to see a difference. That is just a SWAG on my part.

Tell you what, look up some of Frank Proctor's stuff. I think I remember reading something he wrote about his testing on the Glock 34 and reduced power springs. I'm wanting to say that he prefers the 13 pound spring with a specific guide rod??? Maybe if IIRC.

Jones

quote:

Originally posted by jljones:
I think we are confusing a couple of things here. Grip isn't going to fix the issue of the gun being oversprung. Frankly, I don't know why you would want it to. Simply changing out the spring to take out the dip when the slide closes seems to be the wiser choice.

The issue the OP is talking about is not a matter of technique. It is a matter of the gun being so oversprung (usually to facilitate heavier recoiling loads) that at the end of the stroke when the slide is closing, the muzzle dips slightly.

Thanks for the explanation, much appreciated.

My point was the SIG has a higher axis, so I would think changes would be more noticeable. If you're saying there's no difference in the Glock, I don't know. Maybe it's because it's a long slide (what size is the SIG?). Maybe the SIG has a more abrupt stop when it goes into battery and the Glock eases in more.

17-13# is a pretty significant change too. What felt different? Any concern about the pistol beating itself up that low? I honestly don't know...I don't tinker with springs myself.

If you focus on the "muzzle dip" or "muzzle flip" you can probably see subtle differences and start thinking it makes a difference.

But if you focus on the bullet exit" (or smoke ejections, which must follow bullet exit) I think you will notice the amazing thing that the bullet has left the muzzle loooong (relatively) before the pistol has a chance to move detectibly at all.
So shooting accuracy is entirely grip/trigger/flinch control. The pistol reaction is an interesting after-phenomenon. There are other, better, hi-speed videos on the net to demonstrate this phenomenon. That's why people are generally more accurate when they are "surpised" by the shot. Anything you consciously try to do to "compensate" for muzzle dip of flip can only disrupt the targeting accuracy.
Here's a great one:
https://youtu.be/7y9apnbI6GA?t=3

On spring strength specifically, my philosophy was always to choose the heaviest spring that will still allow the pistol to cycle reliably with the ammo you actually use. Wolff gunsprings sells "calibration packs" for some pistols so you can just work up until you find the heaviest one that works.

A heavy spring resists the slide recoil, and reduces the stress of the slide slamming into the frame. It probably also has some miniscule effect at sending more energy in the target direction. Some of my pistols are sprung so heavily that it hurts to rack the slide, but they still cycle reliably. Convenience would be another consideration there.

quote:

Originally posted by Crom:
If you focus on the "muzzle dip" or "muzzle flip" you can probably see subtle differences and start thinking it makes a difference.

But if you focus on the bullet exit" (or smoke ejections, which must follow bullet exit) I think you will notice the amazing thing that the bullet has left the muzzle loooong (relatively) before the pistol has a chance to move detectibly at all.
So shooting accuracy is entirely grip/trigger/flinch control. The pistol reaction is an interesting after-phenomenon. There are other, better, hi-speed videos on the net to demonstrate this phenomenon. That's why people are generally more accurate when they are "surpised" by the shot. Anything you consciously try to do to "compensate" for muzzle dip of flip can only disrupt the targeting accuracy.
Here's a great one:
https://youtu.be/7y9apnbI6GA?t=3

If you are going to shoot one shot, and one shot only, the best I can say about your theory is ok. But, speed and accuracy is far more than grip/trigger/flinch control. By far more. The slide moving and dipping at the end of the cycle plays a huge part, especially when you pour the distance on. The goal is to set up a platform to cause the minimum amount of movement of the slide as the gun fires. To include the dip at the end. The whole point is to have a pistol that returns to the same spot that the shooter is looking at. A gun that returns low is a miss on a fast shot at a head box at 10 yards, and out. It is completely off the target at 30 yards without correction. And that is with great follow through and trigger control. If you have poor follow through or trigger control, AND the sights dip, you have to work real hard to keep up. The more that the sights move, the more work a shooter has to put into the process to make fast hits. The more of this movement that can be taken out as mechanical means, the less correction that shooter has to consciously put into the process. The more heavy lifting that the subconscious can do, the faster the shooter will be.

I've never understood the whole "let the shot surprise you" thing, when I am the one pulling the trigger. The reason why we prep the trigger is to minimize that trigger travel when it comes time to go. But, I believe to shoot at a high level, everyone slaps the trigger to some degree. If you "let the shot surprise you" you are way behind the power curve of speed and accuracy.


A smart shooter who is concerned about speed and accuracy will rig loads, springs, and anything he can to ensure the gun tracks as smoothly from point A to point B. The more work that is front loaded into making the gun flat, the less work that the shooter has to put in to make the shots.

quote:

Originally posted by gentleone:
I did the same test with my G34 gen4. What I discovered was not expected: There was no discernable difference in muzzle dip between the 13 lbf reduced power spring and the 17 lbf factory spring. This puzzled me. I had read from other Glock users that a lighter recoil spring would reduce muzzle dip; and I can FEEL a difference in the recoil impulse. But i did not see any measurable difference in muzzle dip. What's the deal?

The Glock has a lower bore axis and in my experience had less flip and dip than a P series Sig does. It just might be that since there is less to deal with these is less of a difference when you change springs.

quote:

Originally posted by SgtGold:

quote:

Originally posted by gentleone:
I did the same test with my G34 gen4. What I discovered was not expected: There was no discernable difference in muzzle dip between the 13 lbf reduced power spring and the 17 lbf factory spring. This puzzled me. I had read from other Glock users that a lighter recoil spring would reduce muzzle dip; and I can FEEL a difference in the recoil impulse. But i did not see any measurable difference in muzzle dip. What's the deal?

The Glock has a lower bore axis and in my experience had less flip and dip than a P series Sig does. It just might be that since there is less to deal with these is less of a difference when you change springs.

My thought as well. While not a fan of the Glock because they appear to have been styled by a carpenter with a distinct fondness for a 2 x 4 they did get the bore axis noticeably lower than almost any other semi made.

quote:

Originally posted by jljones:
A smart shooter who is concerned about speed and accuracy will rig loads, springs, and anything he can to ensure the gun tracks as smoothly from point A to point B.

Well, you do have a point. It all depends on how you are trying to shoot, and why. For example, speed-shooters often use VERY reduced-power loads, such that they are basically shooting "cap guns".
I am only pointing out that for most common shooting and loads, the bullet has left the barrel long before any part of the slide action can influence it. You are introducing another consideration: how fast can you get back on target.

I got you. Getting back on target is grip, stance, and caliber.