My AR blew up on me today...

[swampratt]

I have been thinking on this for some time as to how it could happen.

Yes possibly a reduced load.

I was thinking possibly a brass case issue.. as in overall length of the case.
I was thinking maybe the case neck was just long enough to reach the rifling in the barrel and seal the bore not allowing the bullet to escape normally.
Then a bunch of pressure will come out of the side of the brass case.
maybe.

 

[SMS]

Me either. They claim that their barrels are MPT tested.

Probably more of a won't than a can't.

If it was a complete BCM gun it might be a different story.

 

[andrsnsm]

I am in no way an NDI expert but I'm wondering what the probability of detection would be for small/tight cracks that would possibly result from this event. Besides, what would it cost to MPI a barrel vs the cost of replacing it. I guess if it were me I would just replace it.

 

[tRidiot]

Guarantee you that liability is the reason both BDM and the commercial places won't test it. They can put all the disclaimers they want on a report for the barrel, but the fact is, they know if you're going to the trouble of having it tested, then you are hoping to be able to use it again. And even if they find it fine and tell you not to use it again, and you do, and it blows, nothing prevents you from TRYING to sue them. Perhaps without merit, but I know from personal experience that means absolutely nothing in today's court system. Someone brings a suit against me that is totally frivolous and without merit and gets thrown out at the first hearing, I'm still out many thousands for legal fees and my insurance still goes up significantly for the rest of my career.

 

[Shadowrider]

I am in no way an NDI expert but I'm wondering what the probability of detection would be for small/tight cracks that would possibly result from this event. Besides, what would it cost to MPI a barrel vs the cost of replacing it. I guess if it were me I would just replace it.

Can't see it being more than $30 to $50 just to get a "yes/no" look on it. Only takes a few minutes. It's worth it to save a $200+ barrel.

Edit: And yes, MPI will show small cracks like a neon sign.

 

[Toney]

[video=youtube_share;JmDfs730wdc]http://youtu.be/JmDfs730wdc[/video]

 

[andrsnsm]

I understand the basics and the utility of MPI, my point is relative to the size of cracks that might result in his barrel. Good stuff for large cracks but what if the crack in the barrel is very small and very tight? MPI is an excellent technique in the right application. The other question is what the barrel is made from. If it is a SS is it of an alloy that is still ferromagnetic? Probably is but if not MPI will not work.

 

[gmar]

Can't see it being more than $30 to $50 just to get a "yes/no" look on it. Only takes a few minutes. It's worth it to save a $200+ barrel.

Yeah, it would very nice if I could salvage my barrel.

 

[gmar]

A machine shop should be able to test it.

Do you have any recommendations in the OKC area?

 

[dennishoddy]

I understand the basics and the utility of MPI, my point is relative to the size of cracks that might result in his barrel. Good stuff for large cracks but what if the crack in the barrel is very small and very tight? MPI is an excellent technique in the right application. The other question is what the barrel is made from. If it is a SS is it of an alloy that is still ferromagnetic? Probably is but if not MPI will not work.

The stainless steel that gun barrels are made from are magnetic. They have multiple alloys in the barrel that make them so. The stainless that is not magnetic is too soft.

I've witnessed hundreds of MPI inspections in the company I used to work for. The tiniest crack can be detected. It may need some magnification, but the shops that perform that service have what it needs.