Advanced Marksmanship Semi Auto Trigger issues

harlikwin

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Minuteman
Sep 2, 2002
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So I'm having trouble with 2 different rifles.

One is G3SG1 clone with a set trigger, the other an M1a with a NM trigger job.

In both cases when dry firing off a bag, I clearly see the reticle jump when I pull the trigger. I've checked a bunch of things on both rifles and the scopes/mounts are tight, so I'm thinking the problem is me.

With the M1a it usually ends up dropping the crosshair down a bit.

With the G3sg1 it tends move the crosshair up and occasionally to one side or the other.

When doing this same practice drill with a Rem700 or other scoped bolt action rifles, I get no/very little movement.

Any input on what I might be doing wrong with either of these semis? I think it may be related to how the hammer is hitting the firing pin and causing a torque on the rifle. But I honestly have no clue how to "fix" or deal with this.
 
Re: Semi Auto Trigger issues

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BOLTRIPPER</div><div class="ubbcode-body">when the reticule twitches on a wire reticule scope....its shook loose.......back to the factory!!!! </div></div>

You know, I thought of this especially with G3SG1 with its older (70's era) Zeiss diavari scope, but I don't think the reticule is a wire reticule (crosshair with range estimation lines like the older rangefinder binos).

With the M14 its wearing a Leupold M8 (6x) scope so again no wire reticule.

I checked over both rifles and they both "seem" tight to the best of my ability to check. But due to the nature of the mounts on both and such it isn't like a bolt gun with super rock solid mounts. Also since I'm seeing this with two totally different rifles I'm thinking it could just be me.

I'm mainly wondering if my trigger pull could be causing the vertical dispersion (the vertical is the worst, horizontal isn't too bad) So far I've tried different up/down positions on the triggers but I'm still getting the jump when the hammer drops.
 
Re: Semi Auto Trigger issues

If it has an adjustable power ring or parallax try twisting it back and forth...if the reticle shifts around when doing so..yeah it may be time to get it replaced.
 
Re: Semi Auto Trigger issues

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: igofast</div><div class="ubbcode-body">What was the issue? Loose mount? </div></div>

So the equipment was not to blame, I generally ruled that out before posting anything here.

The issue, or at least what I think what the issue was is the following:

With a bolt action rifle which is typically striker fired and essentially the firing pin movement is in-line with the barrel (and very quick, i.e. fast lock time). You don't have any sort of weird torques or big parts movements prior to anything lighting off and the force there is, is in line with barrel.

In the case of both the G3 and M1a you have a hammer that is forced forward by a fairly heavy spring, so there is some torque produced there, also the lock time is slower than with the striker fired system. Also when the hammer hits the firing pin there is again a force/torque/disruption of the system. And this is fundamentally what I think the problem is.

Anyhow, the solution I found:
In short, hold on to the rifle for dear life when firing. Essentially with the G3 I found that a combination of a really excessive cheek weld i.e. press down hard with my cheek. And really hauling back on the pistol grip and pulling the rifle into my shoulder, while at the same time "driving" the rifle and applying a forward pressure as well essentially eliminated the reticule jump I was seeing when using a more "relaxed" approach.

I realize this goes against the conventional wisdom with bolt guns where I have used the minimum muscle tension NPA etc approach to good success. But at least in dry fire this "manhandling of the rifle" has basically fixed the reticule jumping around when I dropped the hammer problem. It does make the overall act of shooting harder though.
 
Re: Semi Auto Trigger issues

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: The Mechanic</div><div class="ubbcode-body">As we say in the automotive field "loose nut behind the wheel" </div></div>

I never thought otherwise, which is why I posted it here (marksmanship) instead of the rifle section. But I'm glad you could put that into laymans terms for us.
 
Re: Semi Auto Trigger issues

I don't think you have a serious issue.

I think we all tend to make assumptions about our implements, one being that they are utterly rigid, monolithic objects.

I think not, and I think we are seeing some inevitible flex in the system, including the support. You can't swing/release a mass to impact abruptly with another within the system, and expect things to remain totally inert.

Let me put it a different way.

If it exists exactly as others believe, I seriously doubt it amounts to being a major factor in any rifle inaccuracy. There are far bigger fish to address first.

or...

Think less, shoot more.

Greg
 
Re: Semi Auto Trigger issues

Dry firing is the fine tuning adjustment of your natural point of aim.

The gross adjustment for NPA is to close ones eyes, go through a couple of breathing cycles, then to open your eyes and see where the sights are. To fine tune that gross adjustment you dry fire. If the reticle moves that is where you need to finalize your NPA.

Holding harder does fix it, but with a semi auto you have 3 recoils to deal with so your position is subject to both the first recoil and it's counter recoils. A key reason why people will "double tap" with an auto loader. The bolt pushes the rifle back into the finger of those not activity following through on the trigger.

So your position is very important as the movement will follow the path of least resistance. Magnified in the scope, seen in the reticle movement.
 
Re: Semi Auto Trigger issues

Hi Gregg,

I really started to delve into this after I couldn't repeatedly get the rifle to group worth a damn at 100. Out of a 5 shot string I would have maybe 3 rounds at near 1 moa which is about what I think the rifle can do (g3) while the rest of the rounds were 1-2 MOA away from the group (total ctc groups are in 2-4 moa range). And looking at the pattern of reticule jump while dry firing, the magnitude of movement seems to be about right for dispersions I was observing during live fire. I have yet to verify this during live fire, though I hope to soon.
 
Re: Semi Auto Trigger issues

Hi LL,

I totally agree with your assessment, however in this case I was seeing the reticule movement with the rifle very well supported and almost no pressure/muscle from me. The movement was very significant, and the set trigger is very light hence my though about torques involved. Anyhow, the "hold hard" approach seems to have fixed the issue in dry fire at least. I'll report back as to if it fixed it in live fire.
 
Re: Semi Auto Trigger issues

These rifles are tuning forks, when you light them off, they vibrate, if the rifle was just hanging out, it will vibrate, especially if it is a wire reticle. You don't need a live round to see it, they are still vibrating when the firing pin is released, bolt gun, semi, it's a spring loaded action. So a vibration will happen.

That is why different pressures effect the rifle in different way, you are holding a solid object against the vibrating tuning fork, that changes the harmonics
 
Re: Semi Auto Trigger issues

Smooth trigger control and follow through is the solution to hitting where aimed for most of us. Smooth triggger control is possible with attention to finger placement on the trigger, in a manner which complements the mechanics of the trigger. The trigger should remain in a pulled position until recoil has subsided.

As Frank alluded to, the shooter's contact with the rifle and ground must be consistent, if it's not, recoil will be different, producing a divergent angle/arc effect. When this happens, it's certain, there will be some displacement between point of aim and point of impact.
 
Re: Semi Auto Trigger issues

Hard holds, free recoil, and several stages in between can all be made to work. The commonality comes in the form of consistency.

LL will tell you the NPA's the thing, and he's right.

Sterling Shooter will tell you the bullet always goes where the barrel is pointed, and he's right too.

I use the term, 'the system'. It's the entire process. It includes the firearm, the shooter, and the environment.

When the round ignites, masses start moving, and according to Newton, they all have opposite and equal reactions. So when the bullet's moving, so is the barrel, one a lot faster and farther than the other, but the other, also inevitably.

So while Sterling (Charles) is saying the bullet goes where the barrel's pointed, he means at the moment it emerges. But because the barrel moved, it may or may not be pointed at the precise same spot the sights were pointed before the bullet started moving.

So LL and Charles are talking (mostly) about different points in the bullet's dispatch. LL at the beginning of launch, Charles at the end of the same process.

What happens in between determines what happens way out at the targets.

The sight picture gets everybody aligned for the start. The NPA prepares the body for the recoil cycle.

When the round ignites, the process begins, and if the body recoils relatively consistently, the sight alignment and NPA will prepare the body so the barrel, at bullet emergence, is pointed so the bullet goes where the POA is. The recoil cycle continues until the body returns to a rested position, and if the NPA was good, it leaves it pointed pretty much where it started.

What happens next is just as important, because we're gonna take another shot. How we choose to ride out the recoil cycle determines how consistent the body's motions during the barrel transit time are going to be.

The barrel will only be as accurately/consistently pointed where we want the bullet to go as we are able to repeat the body's motions during the bullet transit.

While intuitively, we may think we need it to be pointed the same as the sights, but that's not really necessary. In fact, what's really needed is that it be pointed the same as the preceding shot, and the same as the next shot. That's what's actually important here.

Nobody's made of steel. The body's gonna move no matter how you approach the recoil. The key is to make its motions consistent. Whether you hold hard, free recoil, or whatever, it's not which one you choose to do that's key, it's how consistently you do it that's most important.

This is why one person's zero can often be different from another's with the same gun and ammo.

If you're gonna do it a lotta times, and you're gonna be straining at it, soon you're gonna get tired, and no matter how much you try, the process' outcomes will begin to drift. If you can get the same consistent outcome without straining, by relaxing instead and 'goin with the flow', so much the better.

Some of us can sustain the strain, some can't, and some don't need to because they choose not to and they can get it to be consistent anyway.

It's a relatively simple matter of <span style="font-style: italic">conscious</span> choice.

For me it's a matter of setting up the shot, then closing the eyes and relaxing completely, I call it 'noodling'. If, when I reopen my eyes, the target and sights are still aligned, I have a good NPA. If not, I adjust the body so on 'awakening', the sights and target still have a good marriage.

Never go to sleep on a bad marriage; it'll always bite in the end...

The harder part is disciplining oneself to remain 'noodled' while the trigger is manipulated.

Don't tense up. This where most shooters screw the pooch. They set everything up perfectly, then unconsciously blow it by tensing up. The get real frustrated because they're doing it right, all of it, and up to that point, they really are. But somewhere in between that moment and when they actual dispatch the shot, they let up their attention to what the body's doing, and it all get wasted.

I say do this for every shot. That's what makes things consistent. If you carefully watch a good shooter and look for these things, that's what you're gonna see, I promise you.

Greg
 
Re: Semi Auto Trigger issues

I don't usually stress this, but for the most part, modern rifles shoot very well and have lot a fewer ailments than many of us would like to think.

The facts simply that are good marksmanship has no shortcuts, needs to be understood at the level of the basic physics involved, requires very good self discipline, and is a perishable skill.

I gotta say, unless someone can point out a specific rifle ailment that was scientifically diagnosed, I'm going to suspect some kind of breakdown in user self discipline or user knowledge as the root cause of a marksmanship (more often called accuracy) problem.

Yes, one nails down the mechanical issues; but in my opinion, the first step is to take the shooters themselves out of the equation. Probably would save a lot of time, and eliminate a goodly bit of running in circles.

Greg
 
Re: Semi Auto Trigger issues

Gregg,
I agree that its usually the shooter, as it was in my case.

Normally like I said I use good NPA/little tension with my bolt guns with good results, it just does not work well in this specific case, and for all I know its just these two rifles.
 
Re: Semi Auto Trigger issues

Interestingly, the point about the bullet always going in the direction the barrel is pointed is to get shooters to think the obvious, if the bullet does not hit where aimed, the shooter did not know where the barrel was pointed. This alludes to the shooter, rather than the gun, or anything else to blame for poor results. The statement, which I use as a tag, I believe, originated with lessons from the USAMU. It's in the SDM course.

One more thing I believe, if indeed the shooter can come to an understanding about where the barrel is pointed he can expect zero displacement in point of aim and point of impact. It is possible, many marksmen at the highest plateaus of competitive shooting have learned how to do it by getting consistency down to the molecular level. Right now, with irons from a sling supported prone position, I can sometimes get most all of my rounds inside 3/4 minute at 100 yards when I go molecular with it all, and I'm just about blind today.
 
Re: Semi Auto Trigger issues

My guess is that either the ergonomics of the stock are incompatible with your physique, or that something is preventing you from getting your NPA right. If you can't relax, you can't shoot well for any real length of time. You can force things, but it won't hold up.

I find that LOP requirements can change with position with the Offhand needing less, and the Prone needing the most.
 
Re: Semi Auto Trigger issues

Gregg,

Well realistically the SG-1 stock isn't adjustable for LOP, it has adj cheek-piece and thats about it. You may be right about the LOP being an issue, but not much I can do about it.

Mine is pretty much this to include the scope. pics:
http://www.hkpro.com/index.php?opti...=97:g3sg1&catid=10:the-sniper-rifles&Itemid=5

Frankly it doesn't seem uncomfortable in any way, I can generally replicate my shooting position from bolt guns, but I would guess my head is much lower on the bolt guns. Other than that I would say my position is fairly similar. At this point, I'm not using the bipod since it raises my position too high to be comfortable.
 
Re: Semi Auto Trigger issues

I am a great fan of Limbsaver slip-on recoil pads, less for recoil reduction, and more for extending LOP. Various versions cn add increments of 1/2" and 1" to LOP. I have extended this with inserts cut from WallyWorld foam floor pads in the housewares department. It's the poor man's stacker LOP adjuster.

Cheekwelds can be adjusted upward with pieces of Foamies peel-off-stick-on neoprene craft foam, in various colors, as well as 2mm, 3mm, and 5mm thicknesses.
 
Re: Semi Auto Trigger issues

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">I am a great fan of Limbsaver slip-on recoil pads, less for recoil reduction, and more for extending LOP. Various versions cn add increments of 1/2" and 1" to LOP. I have extended this with inserts cut from WallyWorld foam floor pads in the housewares department. It's the poor man's stacker LOP adjuster.

Cheekwelds can be adjusted upward with pieces of Foamies peel-off-stick-on neoprene craft foam, in various colors, as well as 2mm, 3mm, and 5mm thicknesses. </div></div>

Gregg,

Thanks for the advice, I do have a factory pad on there and it extends the LOP about an inch over what you see, the problem then is that a limb saver (I use on my other "old" rifles) won't fit over that. The cheekpiece actually rides on two tubes and adjusts up much further than what you can see in the picture so thats a non issue.
Anyhow, I could certainly modify the rifle, but part of the "exercise" for me is to learn how to shoot the historical rifle without buggering it up too much. I do have a MSG90 stock I try throwing on it to see if the LOP increase makes a difference.
 
Re: Semi Auto Trigger issues

UPDATE.

Well... Finally got out to the range to try out my new hold harder technique. Groups sizes generally shrank to something reasonable though I did still have some of the most likely me induced flyers I usually had 4 out of 5 in a decent group with the 5shot usually somewhat off...