Glock accuracy

**tastee** · April 11th, 2016, 09:55 PM

I'm curious if any Glock owners out there have noticed movement in the slide and barrel at different stages of the trigger pull. My Glock 34 shoots the same 7" groups at 25 yds whether offhand or bench rested. I noticed that the slide and barrel raise slightly as the trigger pull is started and then when the trigger breaks it suddenly jumps downward. This is apparent even with the pistol clamped in a padded vise to eliminate the human element. It's easy to understand why this happens when examining the trigger bar's interaction with the firing pin safety and the striker but I can't help thinking this is contributing to the poor accuracy.

**ar15jules** · April 11th, 2016, 10:05 PM

The G34 should be capable of much tighter 25 yard groups. I own several Glocks and have been a Glock Armorer for nine years. The projection on the trigger bar that depresses the firing pin safety should not move the slide "up" at all. The safety should easily press into the slide. Can you push it into the slide with a pencil eraser or such? With the pistol locked in battery are you able to lift the slide from the rails? You may have some type of issue. Hmmmm....

**Hodgie** · April 11th, 2016, 10:09 PM

What kind of real world accuracy are you expecting to get out of a standard production line duty pistol?

**39flathead** · April 12th, 2016, 09:48 AM

Did you buy it new or used?
It's possible some amatuer armorer did some "improvements" if it's used.

**Hawk** · April 12th, 2016, 09:57 AM

Verify the assembly and function of the Firing Pin safety.

**tastee** · April 12th, 2016, 10:04 PM

I purchased the gun 14 years ago brand new but never really evaluated it for inherent accuracy until now.
What kind of accuracy am I expecting? Considering that Glock designed it for competition and it is used widely in that role it shouldn't be unreasonable to expect 3" groups at 25 yards off a bench, even with 50+ year old eyes.
As I look at again what's actually happening is that the rear of the slide is pulling down (raising the muzzle) through the trigger press and then snapping back up on the break. I can press the firing pin safety into the slide with ease. With the slide in battery I can get about a half millimeter up and down play and side to side "rock" on it.

**SteveO666** · April 13th, 2016, 06:59 AM

I am not an expert but I think your 3" group expectation is appropriate and from the sounds of it you have exhausted all reasonable causing and it may be time to call a gunsmith.

I would suggest setting it up to shoot off the benchrest and somehow Record the firing action so that when you take it to the Gunsmith you can show him what you have discovered. I think seeing the Slide/muzzle movement during firing would help understand the issue and may give hint to the solution.
Additionally you may try the same thing with another Glock model to see if you get the same results.

Just my opinion here but good luck.
Steve

**BenFoo** · April 13th, 2016, 09:07 AM

You havent mentioned what type of ammo youre using and whether you've tried different ones.

**laen3145** · April 14th, 2016, 03:59 AM

How often have you shot this GLOCK pistol over these 14 years? I own 9 GLOCK pistols and find that the more often I shoot them, the tighter my shot groups. I probably shoot 2-3 thousand rounds a year using my GLOCK pistols.

**Gunsnwater** · April 14th, 2016, 04:33 AM

You may have a pinched firing pin block spring. First time I installed one I screwed up. I thought it was so easy I didn't pay enough attention to it. When I took it out it was ruined. Lesson learned. It was so bad when it cycled it stopped just short of complete lock up. Then on trigger reset it would finish.