1911 stuck firing pin


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ffg
March 20, 2013, 03:57 PM
Springfield 1911 GI. Primer has put a dent in the breech face and closed up the firing pin hole. This has happened 3 times in different configurations. The latest is with a new Caspian slide after maybe 200 rounds. The first two times were with the original springfield slide. SA repaired it once with a bushing but after the second time I replaced the slide. Normal loads are 200gr LSWC 5gr bullseye. I also have shot a lot of walmart winchester white box also.
In its current form the frame is still SA but it has a wilson barrel, Wolffe springs, Caspian slide, Cylinder and slide hammer / sear / disconector. EGW (.202) slide stop and wilson barrel link. Ed Brown pin set. Had a local gunsmith install / fit the barrel to the new slide and generally check things out but now I'm right back where I started (but with a stack on receipts). Ideas?
Thanks, Brian

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1911Tuner
March 20, 2013, 06:12 PM
Must be awfully soft steel. The original USGI pistols weren't heat treated, and the (likely) 3000 Series steel was dead soft*...and the breech faces didn't peen and deform that badly for 8,000-10,000 rounds.

Are you sure it's not primer flow into the port? That would suggest a headspace problem. How do the primers look?


*Dead soft being defined as the hardness of the steel in its raw, unhardened state.

Blue68f100
March 21, 2013, 09:37 AM
Caspen uses 9mm/38 FP in there slides. Do you have the right FP and did you check to see if the hole the correct size?

ffg
March 21, 2013, 10:54 AM
The pin is .065 and the firing pin hole was .069. I checked with gauge pins because I wanted to see the difference with my springfield pin (.071). The dent in the face is the diameter of the primer and a few thou deep. It looks like I took a .500 dia ball bearing, set it on the breech and smacked it with a hammer. Closed up on the firing pin like a collet.

rcmodel
March 21, 2013, 11:04 AM
Any chance you have been shooting lead-free / clean-range type ammo?

Breach face peening like that was a known problem with lead-free primers when they first came out with it.

I have never heard of such a thing otherwise on a 1911, or any other decent gun.

To have it happen 3 times with two different slides is just a real wonderment!

rc

ffg
March 21, 2013, 12:02 PM
This pistol has approx 5000 rounds thru it, pretty much all 200 LSWC with either bullseye, unique or w231 and Winchester LP primers. The 'issues' seem to have started when I installed a EGW slide stop with a pin dia .203. This was with stock SA barrel and slide. Within 200 rounds the pin was clamped down. I have shot these loads in my other 1911s but not nearly as many.

(edit) the stock slide stop pin size is .195

JRH6856
March 21, 2013, 03:20 PM
The 'issues' seem to have started when I installed a EGW slide stop

Have you considered going back to the original slide stop?

Jim K
March 21, 2013, 03:36 PM
It did happen, though not that quickly, with the original M1911. That is why Colt (sometime in the 1930's, IIRC) went to a hardened steel bushing threaded into the slide, and kept it until they went to a hard slide post-WWII.

Jim

BBBBill
March 21, 2013, 03:41 PM
I've owned 1911s for almost 50 years and worked on them for nearly 35. Can't imagine how a slide stop could cause or even contribute to that problem.

JRH6856
March 21, 2013, 03:46 PM
Can't imagine how a slide stop could cause or even contribute to that problem.

Me either, but going back to the original slide stop would be one way of confirming or eliminating it as a factor. If it is indeed a factor, it would be interesting to know why.

Jim K
March 21, 2013, 04:07 PM
I am sure that the link was changed at the same time as the slide stop (true, ffg?) so I wonder if somehow a too short/long link could cause that problem. I don't see how, but maybe something to kick around a bit.

Jim

ffg
March 21, 2013, 04:13 PM
The original slide stop is in the gun now. I'm going to back off the load a bit and see what happens. This gun has a gremlin in it somewhere. When I first bought it, it would but brass in my forehead. Lowered the port a bit, extended ejector and new extractor fixed that. The next to last or last round would push feed. New mags and springs took care of that. Next was accuracy. Fitted a bushing and the slide stop tightened up the barrel. Now the firing pin episode...
I Will find it...
Thanks!
Brian

ffg
March 21, 2013, 04:20 PM
No, I didn't change the link when I changed the slide stop. Holes in frame are .204, link was .204-.2045. The old stop pin was .195. Just thought I would take up the slack. Yes, probably the barrel was riding the link. But I got rid of the slop that allowed the barrel to push down and the accuracy improved. But in the end the patient died.:eek:
But it was revived...

BBBBill
March 21, 2013, 04:57 PM
Well, your slide stop hole is out of spec at .204". Spec is .201" with .203" being max allowable. The .203" SS is a good fix for that. Not entirely necessary for it to be that large, but the .0005" - .00075" clearance should help alleviate any peening wear on the hole as long as the frame is properly hardened (which ain't very hard). The stock SS pin is under spec diameter. Spec is .200" with .198" being minimum. That means that an in spec gun will have anywhere from .0005" min - .0025" max clearance (half the difference in hole and pin diameters). You have .0045" clearance with the stock SS. Not good for accuracy or longevity IMO. I did have one SA 1911 years ago that egged out the SS hole. SA replaced it at no cost. Never another problem. What is your load? How old are your cases? How loose are the primer pockets?
Perhaps the firing pin channel was drilled too deep, leaving insufficient material around the hole behind the breach face. Spec calls for .250" from the breach face to the back of the clearance channel for the tip. Perhaps a cerrosafe cast is in order. The only other thing I can think of would be to check the slide for proper heat treat.

rcmodel
March 21, 2013, 05:01 PM
But twice with the orginial Springfield slide.

And then again the third time with a new Caspian slide?

It defies logic.

rc

JRH6856
March 21, 2013, 05:34 PM
You have changed slides, and say you currently have a Wilson barrel which suggests you changed barrels. I can't tell from your posts; did the problem occurr with the original barrel or only with the Wilson?

ffg
March 21, 2013, 06:23 PM
This was a SA GI. Pretty loosey goosey.
First time was stock barrel, slide and frame.
Second time was stock slide, frame and wilson barrel.
Third was time was stock frame, Caspian slide and wilson barrel.
The only thing common is frame, oversize slide stop, and my ammo.
I did finally buy a Chrony and scale check weight set. I have always just used the calibration set that came with the scale.

JRH6856
March 21, 2013, 07:34 PM
The load you describe, (200gr LSWC over 5gr Bullseye) is one I have shot for years in several different 1911s with no problems. So I doubt it is that load. Or the Unique or 231 loads if they are that conservative as well.

So that leaves the frame and slide stop as common factors. Right now I'm leaning towards the frame being out of spec in more ways than one. but the easiest to test is the the slide stop. Go back to the original but don't reduce your loads. Try to change only one variable at time.

rcmodel
March 21, 2013, 08:01 PM
Nothing to do with the frame, or slide stop, or link, or pin hole location, or barrel, or chamber can cause primer breech-face peening on two different slides or one slide with a factory FP hole insert repair, plus another new slide of a different manufacture..

Again, It defies logic or reasoning of anything I have seen in 50 years of 1911 fiddling & diddling.

rc

JRH6856
March 21, 2013, 08:31 PM
Again, It defies logic or reasoning of anything I have seen in 50 years of 1911 fiddling & diddling.

I agree. And I agree with your preceding observation. But...gotta start somewhere and it beats staying stuck on " can't happen" when something apparently did happen.

Maybe back to Tuner's question: are we sure we have eliminated primer flow instead of peening? What if the depression around the pin hole isn't peening but gas erosion from gas leaking around the primer?

rcmodel
March 21, 2013, 08:38 PM
Have we eliminated primer leaks or pierced primers and breech face erosion instead of peening??

No we haven't.

PS: Oops! Typing while your were posting!

rc

JRH6856
March 21, 2013, 08:40 PM
Have we eliminated primer leaks or pierced primers and breech face erosion instead of peening??

No we haven't.

PS: Oops! Typing while your were posting!

rc
Great minds and all that. ;)

Jim K
March 21, 2013, 09:22 PM
Well "pierced" primers should be evident and ffg didn't mention that. They are the result of too light a firing pin blow so the primer is not sufficiently supported by the firing pin and flows back into the hole. I have seen that a number of times (and deliberately created it) but I never saw it cause any kind of a dent as described.

And I don't see erosion causing the slide metal to clamp down on the firing pin; erosion would eat metal away, not peen it down.

Jim

ffg
March 21, 2013, 10:05 PM
No erosion evident after SA repair and on new slide although there was a bit on the original slide.
No pierced primers, primers look normal other than a nice little bump where it fills out the dent. The Caspian slide has a raised firing pin hole so the dent is centered. On the springfield slide the dent is like an eyebrow over the firing pin hole.
I'll try to get some reasonable pictures in the morning.
I use a pretty strong main spring to get a good trigger with the cylinder and slide hammer / sear / disconnector. So I'm pretty sure I have a solid hit on the firing pin.
Looked at the tag that came with the Caspian slide and the hardness is RC-40.
Just keeps gettin better and better...

JRH6856
March 21, 2013, 10:31 PM
Well, ffg, so far it seems that, except for you, we are all pretty well agreed that it can't be happening. :rolleyes:

Yes! pictures please. The more detailed the better.

1911Tuner
March 22, 2013, 09:17 AM
Does the primer look "smeared" and shiny in the center? Check the headspace.

ffg
March 22, 2013, 10:30 AM
On the brass picture the top is from the caspian, the lower two are the springfield slide. One of each shows the dimple on the slide decently.
The slide is the caspian. There is a scratch in the breechface from deburring the firing pin hole. It's just cosmetic but since I was bouncing light off the face to show the dent, the scratch is quite prominent.
Headspace was checked, was told it was 'zero'.
My plan for the moment is to go to the .195 slide stop and put about 500 thru it and see what happens. 250 of mine and 250 of factory. Then put the .203 slide stop back in and repeat.

cauldron
March 22, 2013, 10:52 AM
500 rounds on a gun with a part that is out of spec seems like a bad idea. A couple rounds to see what the primers look like maybe.

ffg
March 22, 2013, 11:17 AM
I understand what you are saying, but it takes quite a few before it rears its ugly head. I need to get a few gauge pins(.065-.069) to more closely watch the progress. I will get a bushing put in but I would like to try to figger out what part is causing this. I thinking right now that maybe I need a new frame for the new parts and put the old SA GI back together.

1911Tuner
March 22, 2013, 02:28 PM
You've got some primer flow.

Headspace was checked, was told it was 'zero'.

Was it actually gauged?

There's a common but mistaken belief that dropping a cartridge into the chamber to see if the case rim sits flush with the rear face of the barrel hood is a reliable headspace test. It's not.

You can do a rough check that'll get you pretty close with a resized case, a dial caliper, and a set of automotive ignition feeler gauges.

Work the case under the extractor and slip the barrel into the slide and the case into the chamber. Push the barrel up into the slide the way it is in battery.

Start trying different feeler gauges between the breechface and the case until one enters with moderate resistance.

Measure the case length and add the gauge thickness.

GO...minimum...is .898 inch. NO-GO...excessive...is .920 inch.

JRH6856
March 22, 2013, 02:29 PM
There is a scratch in the breechface from deburring the firing pin hole. It's just cosmetic but since I was bouncing light off the face to show the dent, the scratch is quite prominent.

It's quite prominent on the case head in the lower left of the brass pic as well.

ffg
March 22, 2013, 03:46 PM
The lower two pcs of brass are from the springfield slide. The picture is of the Caspian slide.
Headspace was gauged. I brought it in to Tussey's shop and he checked the headspace and test fired it. He said to seat my bullets a bit deeper in tha case (I let the lead bullets bite the rifling .025). He then added 'go now and sin no more'.:evil:
Well, we might never know the problem on this project. Found a pre '26 style Caspian frame and the slide is being fit to it. The springfield will be returned to its pre-messed with condition. All the recently purchased new parts will then go on the new caspian. I'll have a bushing put in the slide.
Thanks for all the help,
Brian

JRH6856
March 22, 2013, 04:09 PM
The lower two pcs of brass are from the springfield slide. The picture is of the Caspian slide.

Comparing the slide and the brass photos, the scratch measures and looks like an exact match. So a bigger mystery might be how a scratch on the Caspian slide got impressed in the cast fired in the Springfield slide.

Building a new gun and reassembling the original sounds like the best idea, but if the problem persists in the new build, take Tuner's suggestion and confirm the headspace of the Wilson barrel.

Blue68f100
March 22, 2013, 04:21 PM
I don't know if it's an illusion, but the FP seams to be setting down. Have you checked the FP bore closely for spec?

ffg
March 22, 2013, 04:36 PM
Before the slide was damaged I used a set of minus gage pins to determine it I could use the springfield firing pin. The fp hole was .069. My fp was .071 so I used a .065 firing pin. As pictured, the hole is .067 because that was the closest (to .069) reamer I could get my hands on (drills were to short!).

Blue68f100
March 23, 2013, 09:56 AM
I see listing for 0.068" FP all the time but have not measured one to see what they actually measure. Wonder if yours is too far under size.

ffg
March 23, 2013, 12:16 PM
Don't know the spec on firing pin clearance. Have to look it up. Didn't think two thou per side was that terrible though. I'll have a bushing installed in the slide so I get another shot at it.

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