M1 Garand goes boom

[milsurp2.0]

OP thanks for posting this. It's pretty common knowledge that new manufactured commercial ammunition can break the op rod on these guns so why this guy tried a max charge is beyond me. I have to agree that bullet setback is probably the culprit here.

Not crimping is a big no no in reloading for semi autos I've always heard. I only reload Mauser and arisaka fodder. Not that big of a deal for a bolt action.

 

[MoBoost]

Sorry it happened to you, man

Welcome to Chargemaster F-U land - half charge detonation, known issue, happened to Mark at the state match.
Let me guess, cell phone around the reloading table?

 

[milsurp2.0]

Sorry it happened to you, man

Welcome to Chargemaster F-U land - half charge detonation, known issue, happened to Mark at the state match.
Let me guess, cell phone around the reloading table?

Wasn't me. Just a thread on SRF. I don't think it was an overcharge. He didn't crimp and it pushed the bullet back in the casemouth and some funky stuff happened. That's just my guess assuming there wasn't s squib involved

 

[MoBoost]

Not an over-charge - half-charge. Very well documented in PO Ackley book.

I have made a post in the original thread.

 

[Maverick1911]

Sorry it happened to you, man

Welcome to Chargemaster F-U land - half charge detonation, known issue, happened to Mark at the state match.
Let me guess, cell phone around the reloading table?

Does the cell phone potentially cause an incorrect or over charge? Something to consider when I buy one.....

 

[Sanford]

My Sierra book shows the 168 as 3.285 and the 165 at 3.185.

That's probably enough to account for the peculiarity in powder weights.

As for crimping ... if you need to crimp a bottle neck rifle case you're probably over-expanding the case mouth. Most expanders are a little oversize to make bullet seating easier, but they can be reduced with a drill motor and a bit of emory cloth - some people even size without an expander installed in the die which works pretty well when loading boat tails.

...crimping is still, at best, an occasionally necessary evil. Avoid it if at all possible. The other - and in our opinion, better - option is increased neck tension...

From "Reloading for Semi-Autos and Service Rifles".

 

[MoBoost]

Does the cell phone potentially cause an incorrect or over charge? Something to consider when I buy one.....

Allegedly. That's what RCBS told Mark when his Swede exploded ... the load was IMR4350 - you can't overload a Swede with it.

 

[milsurp2.0]

Allegedly. That's what RCBS told Mark when his Swede exploded ... the load was IMR4350 - you can't overload a Swede with it.

Ya idk about that. When I got that swede fake sniper I reloaded for it a little but there was some stuff going on with bullet friction and spike curves due to the long bullet bearing surface. Supposedly one guy that works at Sierra had a Swede blow up with a middle of the road load of 4320. Which is what I use on all my bolt guns.

 

[ASP785]

Not an over-charge - half-charge. Very well documented in PO Ackley book.

I have made a post in the original thread.

This is certainly a possibility but not definitive. What leads me to believe this did not occur is the use of the Chargemaster. Which conversely you seem to believe this is likely the reason that it occurred. I have used the Chargemaster going on a little over 5 years now. I have not had one charge thrown that was grossly underweight. During my research before purchasing it, I discovered that the older models would throw charges well past their set points but display the charge that was input leading the user to believe the charge was correct. In this scenario one could easily have a high charge and not know about it. Thankfully I have a 'newer' version of the Chargemaster that does not suffer this problem.

Could a light charge cause an detonation like this? Yes. However I believe the user would have been able to visually see the light charge. In the end it's all speculation.