[JoeT]

Are these off-center strikes OK?

Yesterday I fired my very first batch of reloads, 50 rounds of 230 plated round nose .45 ACP. Brass was assorted range pick up, primers are WLP, powder is Win 231 from 5.3 - 5.6 grains, with no signs of overpressure that I can see. It was also the first rounds I fired with my new Colt Rail Gun. All my primer strikes seem a little off center in the pistol, but I'm not sure if this is any cause for concern? All rounds fired flawlessly. I also fired some Georgia Arms rounds, and those primers look the same but the primer hits don't look as deep. The GA rounds have silver primers (CCI?) that are maybe a little harder?

 

[Tom Freeman]

Your fine.

 

[Greg Derr]

Are those both from the same gun? First if they went bang- that's fine. Now if they are from the same gun, you have an issue with the lock-up since the barrel locks into one position for one shot, and another for the next- not good. Your primers should get strick all the same- even of off center a tad. And yes some primers are harder than others- CCI being harder than the Winchester.

 

[RickB]

If the gun goes bang every time, and hits the target every time, there's no problem.

 

[JoeT]

Are those both from the same gun? First if they went bang- that's fine. Now if they are from the same gun, you have an issue with the lock-up since the barrel locks into one position for one shot, and another for the next- not good. Your primers should get strick all the same- even of off center a tad. And yes some primers are harder than others- CCI being harder than the Winchester.

I was shooting two Colts, and I lost track of which brass came out of which. The one that's more centered I believe came from my S80 Gov't and the one that's way off is the Rail Gun. I know this because the first 50 rounds I shot were my reloads and they were all through the Rail Gun and they were all in the same spot as the case on the right.

 

[theheadbud]

Good post and thanks for the info! I too have the same "problem" in my Series 70 repro. Now I can relax too.

 

[RickB]

Have we discovered a problem? That is, if the gun goes bang and hits the target, what's the problem?

 

[theheadbud]

Have we discovered a problem? That is, if the gun goes bang and hits the target, what's the problem?

Apparently there is no problem. Just asking if there was.

 

[eagle0711]

I agree. I've had guns do that and it doesn't even effect accuracy. The advice I got was to forget it., Best Lyle


If you can't beat him, take him with you.

 

[3jaw]

The one on the left is fine. The one on the right is a little too close to the edge of the primer for my taste and could be an indication of about 3 different things.(Although, if it goes "Bang" every time, you should be okay.)

It could be:

1) Firing pin hole drilled in the wrong location.

2) The upper barrel lug engagement is shallow.

3) The upper barrel lug engagement is deep.

4) If it is offset to the left or right, the hole could be drilled off center, the barrel fitted off center, or I can even see where the slide being off center could affect the firing pin strike a little bit.

5) A combination of the above.

You can use the following test to get an idea of where the problem lies. Take a marker and make a small mark on the head of the case near the edge. Load the round with the mark pointing up and fire the gun. If the primer strike is toward the bottom of the primer, the lug engagement could be deep. If it is toward the top, then the lug engagement could be shallow. If it is toward the left or right, check the firing pin hole, barrel fit and slide fit.

As an alternative to the above test, you can take an empty fired case and knock the spent primer out. Remove the firing pin and spring from the slide. Place the case in the chamber and let the slide come forward and lock the barrel in place (you probably want to pull the extractor out to keep from damaging it). Shine a light from the rear of the slide through the firing pin hole and sight down the barrel. The hole in the case is larger than the firing pin hole and any mis-alignment will be immediately obvious.

Hope this helps,
Greg

 

[JoeT]

The one on the left is fine. The one on the right is a little too close to the edge of the primer for my taste and could be an indication of about 3 different things.(Although, if it goes "Bang" every time, you should be okay.)

It could be:

1) Firing pin hole drilled in the wrong location.

2) The upper barrel lug engagement is shallow.

3) The upper barrel lug engagement is deep.

4) If it is offset to the left or right, the hole could be drilled off center, the barrel fitted off center, or I can even see where the slide being off center could affect the firing pin strike a little bit.

5) A combination of the above.

You can use the following test to get an idea of where the problem lies. Take a marker and make a small mark on the head of the case near the edge. Load the round with the mark pointing up and fire the gun. If the primer strike is toward the bottom of the primer, the lug engagement could be deep. If it is toward the top, then the lug engagement could be shallow. If it is toward the left or right, check the firing pin hole, barrel fit and slide fit.

As an alternative to the above test, you can take an empty fired case and knock the spent primer out. Place the case in the chamber and let the slide come forward and lock the barrel in place (you probably want to pull the extractor out to keep from damaging it). Shine a light from the rear of the slide through the firing pin hole and sight down the barrel. The hole in the case is larger than the firing pin hole and any mis-alignment will be immediately obvious.

Hope this helps,
Greg

I think the barrel is fitted to the bushing slightly off center. Though the barrel to bushing fit is nice and tight. I noticed the wear marks on the barrel just forward of the chamber are more prevalent on the left side, and almost non-existent on the right side.

 

[3jaw]

I think the barrel is fitted to the bushing slightly off center. Though the barrel to bushing fit is nice and tight. I noticed the wear marks on the barrel just forward of the chamber are more prevalent on the left side, and almost non-existent on the right side.

I would think it would take a lot of offset from the bushing to make the primer strike be that far from center. Does the barrel feel like it is binding when going into battery?

 

[JoeT]

I would think it would take a lot of offset from the bushing to make the primer strike be that far from center. Does the barrel feel like it is binding when going into battery?

Not at all. Once I greased the slide rails and shot a few rounds the action slicked right up. I don't believe it was" bad" to begin with.

 

[JoeT]

I did what you said and stripped the slide down, and popped an empty, deprimed case in. The case wasn't totally centered but the extractor seems to be a bit ... off. It works, but according to the extractor tuning how-to it's about as jacked up as a football bat. For one, the tension is too much. A loaded round will not fall out no matter how hard I shake. Two, the extractor head impacts the body of the brass quite a bit when I press the brass firmly against the breechface. Enough that when I stop applying the pressure to keep the brass seated on the breechface, the extractor pushes it off the breechface quite a bit.

I slightly adjusted the extractor and now the firing pin channel and the primer hole in the brass line up straight... but the extractor still needs to be properly fitted. So, it works just fine but isn't optimal. I'll just have a professional change my extractor when I have the EGW thumb safety installed.

 

[3jaw]

I rotated your 2nd picture to where I thought the extractor mark was on the on the right side like it would be in when it was chambered (lined up with the "M" stamped on the head.) If this is right, then the extractor is shifting the case in the chamber up and to the left to get the primer strike where it is now.

Enough that when I stop applying the pressure to keep the brass seated on the breechface, the extractor pushes it off the breechface quite a bit.

Can you post a picture of the underside of the slide showing this? I would be interested to see if it is pushing it off the breechface on the same side as the extractor or the opposite side.

Sounds like you may be onto something.

Greg

 

[JoeT]

I rotated your 2nd picture to where I thought the extractor mark was on the on the right side like it would be in when it was chambered (lined up with the "M" stamped on the head.) If this is right, then the extractor is shifting the case in the chamber up and to the left to get the primer strike where it is now.



Can you post a picture of the underside of the slide showing this? I would be interested to see if it is pushing it off the breechface on the same side as the extractor or the opposite side.

Sounds like you may be onto something.

Greg

It's pushing the case off the breechface on the same side as the extractor. I checked the extractor in my S80 Gov't model and can clearly see light between the tip of the extractor claw and the brass. In the Rail Gun the tip of the claw is touching and applying pressure to the brass, pushing it off the breechface.

 

[WalterGC]

If the action's properly locking up, you'll get center strikes. Might not be a problem for some, but I'd want mine to behave.

 

[Xventurashooter]

The location of the barrel in the slide determines where the firing pin hits the primer. Adding or reducing extractor tension will not move the hit on the primer.

 

[3jaw]

The location of the barrel in the slide determines where the firing pin hits the primer. Adding or reducing extractor tension will not move the hit on the primer.

For the most part, I agree with you. The location of the barrel in the slide and the firing pin hole location are the major determining factors in where the firing pin hits the primer. I am thinking it may be a combination of things causing this. If the chamber is a little loose, the extractor could jockey the case around. This, along with the below statements could explain the problem.

I did what you said and stripped the slide down, and popped an empty, deprimed case in. The case wasn't totally centered but the extractor seems to be a bit ... off.

Two, the extractor head impacts the body of the brass quite a bit when I press the brass firmly against the breechface. Enough that when I stop applying the pressure to keep the brass seated on the breechface, the extractor pushes it off the breechface quite a bit.

I slightly adjusted the extractor and now the firing pin channel and the primer hole in the brass line up straight...

In the Rail Gun the tip of the claw is touching and applying pressure to the brass, pushing it off the breechface.

Is that with or without the barrel in the slide?

Greg

 

[JoeT]

For the most part, I agree with you. The location of the barrel in the slide and the firing pin hole location are the major determining factors in where the firing pin hits the primer. I am thinking it may be a combination of things causing this. If the chamber is a little loose, the extractor could jockey the case around. This, along with the below statements could explain the problem.



Is that with or without the barrel in the slide?

Greg

Without.