Random Stuff…

Posted on by August 23, 2014

This one from PP… 🙂

Tupperware

 

And sometimes PHDs ARE good for something… Got in a discussion yesterday morning with the former Marine Sgt (twice), now PHD about ballistics and differences between 7.62 and .308…

An hour later I get this…

corrected 762 vs 308

And an I told you so email… sigh  Hell, as far as I know, he may have BEEN the one that did this research…

I really hate it when he rubs it in…

Comments

Random Stuff… — 18 Comments

  1. Pressures should be the same. Both cartridges are 62,000 PSI and 50,000 CUP While the two ways of measuring are similar, they are not identical especially at higher pressures.

    Also, I expect that he intended to use the units “grains” rather than “grams” in his graphic. At approximately 30 grams to the ounce each round would weigh over five ounces (or three to the pound) if the cases are 165 grams. The twenty grain difference in case weight results in about 2.5 grains less powder capacity in military cases.

    Otherwise, a great graphic.

    -Joe

  2. One less thing I don’t have to worry about. Yet.
    But unlike .223/5.56, I was unaware. The civilian round is more powerful?

  3. ERJ- He specifically said the 7.62 was lower pressure… Yeah, should be grains not grams too.

    Ed- Yes sir, it is.

  12. Thanks for posting the ballistics, but Josie has not problem firing either. She slings them downrange just fine.

  14. The difference in headspace is really important for those of us who reload. Old bolt actions like the Ishapore Enfield could have case separations in just a few uses if you resize full length, and that is not good for the bolt either, which does not lock up front by the breech end of the barrel. Check out this video that shows an M1 Tanker damaged by .308 steel cased ammo. I think this was probably due to headspace differences more than pressure specs. https://www.youtube.com/watch?v=TleMPyDq56s

  16. Caveat Emptor. You can’t be too careful with some of this off-shore ammo. The QC is just not consistent. Some lots run OK, some are accidents waiting to happen. The following link shows photos of some Korean 30-06 ball ammo that suffered case failures—

    http://www.msgunowners.com/t3359-korean-surplus-ammo-danger

    No good deed shall go un-punished. I had a customer on a limited budget who really wanted to get into shooting the M1 Garand. I helped him get one of those assembled (with surplus parts) by Century Arms. He then ran about 400 rounds of the Korean crap through his M1 (at the time, who knew?).
    Shortly after, he brought me six cases with the same failure as those in the above link. I inspected his M1, and thankfully the rifle and shooter were none the worse for wear.

    On a side note, that Century M1 was assembled on an Alpine receiver (no markings on the receiver heel). For those interested, here is a link to some history—

    http://www.m1carbinesinc.com/carbine_alpine.html

    The above site is an impressive collection of years of research about the commercial production of the M1 carbine.
    Warning! Five Star time sink! Enjoy.