Primer strike from chambering

[LMT/556]

The extractor has to snap over the rim on every loaded round in AR platforms, don't see how it would make a difference.
Pistols are different the breach face is cut to allow the round to slide up and in vs snapping over the rim. Closing the slide on a chambered round was a good way to compromise a German SIG extractor.

[Uni-Vibe]

The extractor has to snap over the rim on every loaded round in AR platforms, don't see how it would make a difference.
Pistols are different the beach face is cut to allow the round to slide up amnd in vs snapping over the rim. Closing the slide on a chambered round was a good way to compromise a german SIG extractor.

Maybe on Stoner action, stripping a round out of the magazine slows the bolt down enough to avoid extractor stress. Whereas single hand feeding lets the bolt hammer the case head too fast.

[26 Inf]

I've fired once-dimpled 5.56 with no ill effects. Interesting that 26Inf can duplicate the problem by a dozen or so chamberings.

The items I posted weren't my personal experiences. Found from different sources several years ago. The one from 1965 probably isn't relevant as there have been primer changes.

[26 Inf]

Maybe on Stoner action, stripping a round out of the magazine slows the bolt down enough to avoid extractor stress. Whereas single hand feeding lets the bolt hammer the case head too fast.

I don't know enough to say that isn't true. However, service rifle competitors single load 30 rounds during the National Match Course, many of them use either a bob-sled/single round follower or direct load into the chamber - extractor breakage hasn't been a problem with the guys I shoot with. (maybe I should say 'shot with' since COVID)

[Uni-Vibe]

I don't know enough to say that isn't true. However, service rifle competitors single load 30 rounds during the National Match Course, many of them use either a bob-sled/single round follower or direct load into the chamber - extractor breakage hasn't been a problem with the guys I shoot with. (maybe I should say 'shot with' since COVID)

Agreed. National Match guy I know uses a sled, never noted any ill effects either.

[ThirdWatcher]

... From 1965: A soldier in the 82nd, during the operations in the Dominican Republic, chambered a round while preparing for guard duty that had been chambered and ejected several times. His weapon discharged, though it was on "SAFE" according to witnesses at the scene. The soldier was negligent about where his weapon was pointed and the round killed a local child.

The soldier was court-martialed and acquitted. Investigators were able to repeatedly duplicate the incident by chambering a round from the magazine several times. They discovered that this malfunction, firing when a round was chambered, could be duplicated at around 10-15 chamberings. They also found that at about 10-15 chamberings, many rounds did the opposite and the primers became desensitized enough that the rounds would not fire...

I had no had no idea the (knowledge of) the problem went back so far.

Ironically I served in LE with a guy who jumped into DR with the 82nd. He said he could hear all the shooting on the ground and the last thing he wanted to do was land in the middle of it. Great guy...

[R0CKETMAN]

Once chambered always goes to training pile in Go To guns....

Even in my 1911s and Glocks where set back is more prevalent #cheapinsurance

[rocsteady]

Part of our routine at the beginning of day shift when removing AR from it's overnight safe in the office was to check the first couple rounds of each mag and if dimpled, were to put into the "range" bucket and replace with new round.