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Discussion Starter #1
Hi - I was out last week and was testing several brand for best accuracy. After just over 100 rounds I had gone thru CCI-40gRNCu, and Fed Black Pack 36gHPCu and was near 35 rnds of Fed AutoMatch when I had a round blow up in my face. The bolt did not completely close, over a quarter inch open when it fired. The case blew out the side, but the bullet went forward - mostly. When I was cleaning that night, I found several tiny 'crescent shaped' shavings of lead inside the action, even around the hammer and springs. Some seemed to have copper coating so they were from either the CCI or Fed BP (both HV) since the Fed AM that blew was RNL. I had had some of the stovepipes of fired cases but that has occurred with most brands and also with my Sav-64, so doesn't seem to be an issue? I keep the action lightly lubed with silicone grease (that caught the shavings), but nothing at the chamber face. There was very little residue in that area, partly 'cause it got blown away? The blown case was too mangled to determine anything from it. Anyone have this sort of thing happen? Any suggestions as to what may have occurred?
 

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Could the primer have not been completely seated? Sitting proud and crushed by the bolt? Could a piece of debris got between primer and bolt? Could the pin have become jammed in the forward position, possibly by some debris in its channel?

I once knew a guy shot several times through the hand by his own 1911 going full auto. Turned out the pin got jammed forward by a tiny pice of steel that got loose from the spring. When he cycled in the first round it went full auto on him.

If possible, a close examination of the primer from the exploded round. It would have been blown back, but does it have a pin dent in it?
 

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The bolt might have picked up the round incorrectly and caused the priming compound in the rim to set off the round. It would help if you could post a photo of the round.
 

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might try disassemble clean and dry everything real good including firing pin and springs, brake cleaner and carb cleaner in spray cans are easy, cleans pretty good, leaves no residue, then if you want to lube maybe try a little powder graphite
or something that leaves no residueof any sort to might cause any type of hang up.
but I'm not an expert just a hobbyest
 

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Could the primer have not been completely seated? Sitting proud and crushed by the bolt?
Not likely, since we're talking about a rimfire cartridge.

What can happen, though, is that as the gun's action becomes fouled debris may slow chambering and jam an extractor or firing pin in such a way that when the bolt goes forward and the cartridge meets resistance in the dirty chamber the extractor or firing pin can hit the rim, firing the round out of battery.
 

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Scary stuff. Hope you weren't injured. Didn't say what firearm you were shooting.
 
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Discussion Starter #8 (Edited)
Pics for "Out of Battery"

HI - First, sorry I didn't say that this was in my M60. Just since it was the 60 forum I didn't think to. Next, I was in a hurry this AM and didn't have pics but I do now. I'll show a couple of the case damage and one showing the end of the case. It shows a really deep Pin strike and at the 8 o'clock position you can make out the extractor mark, but I don't think the round was fully seated into the chamber. Maybe stuck partway in with that last 1/4" hanging out? I would guess these two marks are exaggerated due to the firing pressure when not supported by the bolt or rim? The round did NOT eject, I had to pry it out with forceps I carry in my bag.
When it went off a good bit of stuff flew up and out - glad I wear the glasses when firing. I just had double corneal replacement a year ago and would hate to lose one:eek:

As for residue, there wasn't a lot in the chamber/bolt face. Although there had been about 100 rounds before this happened, the chamber area wasn't very dirty,except for the powder from the blowout. I don't put lube in either of those areas, just on the action and bolt top-bottom-sides. And I had just cleaned the complete gun before that range session - full strip-down incl action.
Anyways, this just shows that even with .22s safety equipment is a good idea:embarassed:
DSCN7094.JPG DSCN7100.jpg DSCN7109.jpg

 

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HI - First, sorry I didn't say that this was in my M60. Just since it was the 60 forum I didn't think to.
Nope, my sincere apologies. I didn't look at which forum the post was in. As my oldest father used to say "RTFI" (read the info). The only guess I can make is due to the shavings you found something must have gotten between the cartridge and bolt face. Glad you're ok!
 
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HI MikeM - I do the same thing, going from one forum to another. As for the shavings, there wasn't enough to hold the case a quarter inch out of the chamber unless they were stuck in the chamber itself, just some fine bits from the bullet(s?). Here are some pics of the ones I found in my trash can:embarassed: - I didn't think to save them while cleaning :s:.
That's a CDN dime for reference. Note the copper on some - the Fed AM is RNL, not copper clad, so those are from either the CCI-MM-RNLCu or the Fed BP-HPCu. So these are from much earlier shots - an ongoing problem. . . it seems. I've never noticed any shavings before, but I'm guessing these are from the Fed BP as it's 36gHP which is a bit higher velocity than the CCI. The higher power could be running the bullets thru a bit faster and 'mis-aligning' just that tiny bit?

DSCN7113.jpg DSCN7115.JPG DSCN7117.jpg
 

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One of my model 60's was shaving little crescents of lead like yours. What I eventually found, was that the thin edge of the breech, where the angled cutouts for the extractor clearances are, was bent in slightly. I am guessing a stove pipe jam may have caused it.
The first thing I would check on your rifle would be if a unfired round slips into the breech all the way, with no resistance. If the breech is bent in like mine was, it may cause a round to catch on the sharp edge and not seat flush with the breech face.
 
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Those are some pretty big shavings, especially for 22. I have a few Beretta 21a Bobcats and one of them shaved from time to time but nothing like that. I polished the port and feed ramp and it seemed to help. If any of the rounds you were using had a heavy enough coat of wax, it could definitely pick up a piece on the way in the breech. Hope you can figure out what's causing it. And again, very glad you weren't injured!
 
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