DON'T let the bolt slam home on an already chambered round

Don. said:
I've never had that happen with my Springfield Armory using milsurp ammo, but it's good to know.
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Have you been putting a round into the chamber & letting the bolt fly? This is not a Springfield vs Norinco issue... This is an issue about the proper use of a firearm with a free floating firing pin. NEVER put a round in the chamber of an M14 & let the bolt fly onto it, what happened to the OP can happen to your Springfield.

Regards
Jay
 
By the way, the warnings about chambering a round and letting the bolt fly into battery applies to all M14, M1A, M1 Garand and M1 Carbine rifles.

It is a very bad idea on any semi or full auto rifle or handgun. It is a very bad habit. Always feed ammo from the magazine or belt.
 
Glad to see you weren't hurt. It's an unfortunate lesson, but it reminds us all "Learn from the mistakes of others - you'll not live long enough to make them all yourself".
 
The safety bridge does not come into play until the bolt is rotating into firing positions. If the bolt is stopped before the bridge, the firing pin continues on until it hits its had stop. If there is a round in the bolt, the firing pin will hit the primer.


Sluggo_m14 said:
Is the mini-14 subject to this as well? Isn't the safety bridge supposed to help prevent this?
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yomomma said:
The safety bridge does not come into play until the bolt is rotating into firing positions. If the bolt is stopped before the bridge, the firing pin continues on until it hits its had stop. If there is a round in the bolt, the firing pin will hit the primer.
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Didn't want to comment on the safety bridge failure aspect, lest this become viewed as more Norc slagging. But in my opinion, it should have stopped this, operator error or not. That said, it likely can't be relied upon solely to, when developing the Garand they lightened the firing pin to address slam fires, some feel this was the sole protection engineered into the design, and the safety bridge a side factor. There is some debate about the actual initial design purpose of the safety bridge as well. I feel it should prevent slam fires whether that was its initial design intention or not (it clearly must retract the firing pin on bolt opening as well, some feel this and supporting the bolt were its original and sole purposes), in a well machined receiver it certainly is capable of the job.

-The safety bridge will hold back the firing pin (if working correctly), even in a slam fire situation / not from hammer strike alone, retarding the pin until the bolt rotates into battery.
-The firing pin can only protrude .06" max from the face, unless the gun is woefully out of spec. The bridge if working would stop the pin before meeting the primer of a chambered round.

Open to the debate on this.
 
Ardent said:
Didn't want to comment on the safety bridge failure aspect, lest this become viewed as more Norc slagging. But in my opinion, it should have stopped this, operator error or not. That said, it likely can't be relied upon solely to, when developing the Garand they lightened the firing pin to address slam fires, some feel this was the sole protection engineered into the design, and the safety bridge a side factor. There is some debate about the actual initial design purpose of the safety bridge as well. I feel it should prevent slam fires whether that was its initial design intention or not (it clearly must retract the firing pin on bolt opening as well, some feel this and supporting the bolt were its original and sole purposes), in a well machined receiver it certainly is capable of the job.

-The safety bridge will hold back the firing pin (if working correctly), even in a slam fire situation / not from hammer strike alone, retarding the pin until the bolt rotates into battery.
-The firing pin can only protrude .06" max from the face, unless the gun is woefully out of spec. The bridge if working would stop the pin before meeting the primer of a chambered round.

Open to the debate on this.
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Bridge issues have come up time and again on most manufacturers...
 
Jay said:
Have you been putting a round into the chamber & letting the bolt fly? This is not a Springfield vs Norinco issue... This is an issue about the proper use of a firearm with a free floating firing pin. NEVER put a round in the chamber of an M14 & let the bolt fly onto it, what happened to the OP can happen to your Springfield.

Regards
Jay
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I'm certain that I have at some point, but like I said, it's been fed a steady diet of milsurp with hard primers. The Norks I've been around have always had some problem. A former acquaintance of mine had to replace basically everything but the receiver on his. I never had the desire to go Chines after that, unless it was an AK. YMMV.
 
There is a bridge in the receiver that’s supposed to
“hook” the tail on the firing pin as the bolt is clos-
ing and prevent the pin from going forward, but
that’s only according to the blueprints. The tail of
the firing pin then aligns with the bridge to allow
the pin to go forward after the bolt is closed. It
hardly ever works all the time and frequently does-
n’t work at all. Not all bridges are dimensionally
correct enough to function as designed and can
allow the pin to slip through as the bolt closes.
Not a “quality” issue since it’s known to infect the
superb “real” M14 receivers as well as cast junk
from China. If the bridge has too tight a toler-
ance, it can cause cycling malfunctions and possi-
bly the destruction of the firing pin as it contacts
the bridge when the bolt unlocks after firing. That condition is rare but could be one reason many receivers
tend to come out a little larger in the bridge area.
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Zeideker " Reloading for the match M14"
 
I don't think it was the safety bridge, as I had done some safety bridge inspections and playing around with the gun and safety bridge when it was newer. I was pushing on the firing pin and such as I would let the bolt close slowly to see if it prevented the pin from moving forward until it was in battery. It worked until the bolt was almost completely into battery. That's how I expected it to work.
I believe the bolt was almost into battery when it blew up, judging by a couple marks on the recess' in the receiver for the bolt lugs.

Derek
 
CanuckR said:
I don't think it was the safety bridge, as I had done some safety bridge inspections and playing around with the gun and safety bridge when it was newer. I was pushing on the firing pin and such as I would let the bolt close slowly to see if it prevented the pin from moving forward until it was in battery. It worked until the bolt was almost completely into battery. That's how I expected it to work.
I believe the bolt was almost into battery when it blew up, judging by a couple marks on the recess' in the receiver for the bolt lugs.

Derek
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There is zero doubt the bridge when made correctly can prevent this, in a new LRB for instance, you could do this all day long though extremely ill advised. I dropped the bolt of my LRB on a soft commercial primered case (no bullet of powder) a bunch times with the mag out, zero ignitions or even marks. Also just did the same on a Federal (soft primer) primed case in my .308 Krieger barrelled Garand same results, no issues, I dropped it 40 times watching TV just to see.

As for perhaps firing mostly in battery as per your bridge observations on your rifle, Norc bolts are also weaker than US. Little debate on that with the headspace growth we can see in them, they're generally softer. One old one I punched for hardness was very soft, and another just swell, have a third one blown up on the bench that blew just like yours and I'll get the bolt hardness tested, for case and core. So with a weaker bolt and not full engagement, you could get bolt failures like this I suppose even if the bridge did most of its job, so your bridge inspection could well have been just swell.

What we all seem to agree on, even though it sounds like it may not have been the critical factor here, is you can't count on the safety bridge to prevent a slam fire as you know better than any of us. Its reliability and even initial design purpose are both suspect, this said if you're paying big bucks such as for an LRB, I would absolutely expect it to be machined properly and work, as it certainly can. On a Norc? Wouldn't expect it to at all unfortunately, though it certainly would be nice if it did. Every M14 manufacturer has had bridge failures, but few would debate you're going to find more the cheaper you go. This all said, with your evidence mentioned there and prior bridge inspection, starting to wonder if this was a bolt failure. Rather than a bridge failure that is, with what you've said about your bridge and the marks indicating it was almost in battery when it blew. This mirrors the blown up Norinco bolt I have at home as well.

All in all no matter how it came together, it's a happy story as you're OK. I was wondering if it appeared it had gone most of the way into battery before failing, as this could explain how the one I mentioned above failed, and I've read of several other bolt failures in the same manner as yours, exact same damage too. I can't help but wonder if we're seeing slam fires with the bolt just slightly out of full lug engagement, on commercial .308 primers (soft). Combine that with weak bolts and you'll be seeing failures exactly like these. You may well have just done some of the best incident investigating possible without meaning to. :) I would certainly say take this opportunity to fit a US bolt.
 
####, son! I didnt know that about garands and m14s. good to know. I had done that on ar15s and pistols before though. Guess i wont do that again.
 
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