Failing proof

[hobbesy]

Hypothetically.

If an AR barrel fails proof due to a bulging of the case, can the barrel be sent to back to another proof house to get retested without any 'work' being done on the barrel?

What are the ramifications of doing so?

TIA

[Mattnall]

If the case bulges, the chamber is screwed. It'll need recutting.
But then I guess all cases 'bulge' to some degree on firing, it'll be a case of how much.

However, if it passes proof then it will be stamped has having done so, and all the relevant checks will have been done and the firearm/barrel is 'in proof'.
Offences are selling/transferring or offering for sale or transfer whilst not being in proof so I perhaps in this case it will be OK to pass on.

The proof system is broken. Pushing something to its limit and if it survives it gets marked as OK. The stress may have weakened the barrel so much so that it could fail with a normal service loading on its next firing, or possibly sooner than it would have done if it had only fired standard loads.
Barrels often fail to be proofed for whatever reason.
I have seen barrels not be proofed (proved?) because the GO gauge(s) wouldn't go. Several other sets of gauges indicated the chamber was close to being too long and any work on it could mean the NOGO would go. In the end, without any intervening work being done, the same proof house passed the barrel using a provided set of gauges.

[hobbesy]

If the base of the case has bulged to such a degree would the barrel be returned or destroyed?

How does the rest of the upper then get tested and passed or should it all be written off?

I do agree with the whole proof thing out of date and not fit for purpose.

[Mattnall]

That looks more like over pressure round than a chamber problem.
The bottom part of the case is not all contained in the chamber as it's where the case sits in the bolt face and there is a small gap.

If a firearm fails proof it is usually returned to the owner, still cannot be sold or transferred as it is not in proof.

If this is a loading issue then the barrel is most likely OK (for now), if the chamber is very tight then that could cause pressure problems.
The Barrel may not be scrap, it could have the chamber re-cut or even set back by taking the barrel extension off and shortening the barrel slightly and then re-cutting the chamber again. The rest of the upper is not pressure bearing so shouldn't be distorted, unless the case ruptures.

This is very specific for a hypothetical instance
I'd like to see the barrel before passing it on, also see the stated reason it failed proof. As I said above this looks like an over pressure situation which, if contained, is what the whole proof procedure is meant to check. The rifle didn't fail, the cartridge did, and almost catastrophically.

[hobbesy]

Thanks for all the info, don't want to get into specifics at the moment. I'm also wondering what sort of damage could it have done to the bolt and carrier and how would I even check?

I understand the proof house up the loads by 30% but how do they even know what powder the cartridges are using or do they completely load their own ammunition and fire that?

All seems very odd to say the least.

[Gun Pimp]

"I understand the proof house up the loads by 30% but how do they even know what powder the cartridges are using or do they completely load their own ammunition and fire that?"

How may I ask do you come to understand that? I can't imagine any rifle would stand a 30% overload.......... But yes - they do load their own proof rounds.

[Mattnall]

The B'Ham proof house defintely loads their own ammunition and tests the ammo first to get the performance they desire.

I understand they look for a percentage pressure over the standard CIP loading, or possibly one of the other 'standards' out there, and then use that.
I had a tour of the ammo facility there and there is not much they couldn't load. They managed to work out a load for me to match my pet loading but using a different powder (curse you REACH) and the performance so far on the range is exactly the same between the two.

[hobbesy]

"I understand the proof house up the loads by 30% but how do they even know what powder the cartridges are using or do they completely load their own ammunition and fire that?"

How may I ask do you come to understand that? I can't imagine any rifle would stand a 30% overload.......... But yes - they do load their own proof rounds.

Information I had been given from a source, not from anyone at the proof house so may have been steered wrong.

[hobbesy]

The B'Ham proof house defintely loads their own ammunition and tests the ammo first to get the performance they desire.

I understand they look for a percentage pressure over the standard CIP loading, or possibly one of the other 'standards' out there, and then use that.
I had a tour of the ammo facility there and there is not much they couldn't load. They managed to work out a load for me to match my pet loading but using a different powder (curse you REACH) and the performance so far on the range is exactly the same between the two.

I would be right to understand that they would have done countless AR straight pulls, and know exactly how to load a round by releasing the handle and not pushing it forward like a bolt.

[Chapuis]

The B'Ham proof house defintely loads their own ammunition and tests the ammo first to get the performance they desire.

I understand they look for a percentage pressure over the standard CIP loading, or possibly one of the other 'standards' out there, and then use that.
I had a tour of the ammo facility there and there is not much they couldn't load. They managed to work out a load for me to match my pet loading but using a different powder (curse you REACH) and the performance so far on the range is exactly the same between the two.

When our club visited the Birmingham proof house some years ago we were informed that the majority of the proof ammunition used was in common chamberings and obtained from commercial ammunition manufacturers, however the less common chamberings they loaded themselves. I was very impressed by their very substantial collection of reloading dies that they had amassed. I suppose that they will continue to add to the collection as new cartridges come out.