Big bore AR: 50 beowulf, 458 socom, or 450 bushmaster?

[L1A1Rocker]

I'm thinking about a big bore AR but don't know much about them. I'd most likely cast my own bullets so the expense of bullets is not a factor for me. Also, are all three proprietary brass? I'd like to be able to make my brass from existing stock - like the 300blk is made from .556.

Well, that's my thoughts so far. Any of you with knowledge on this and/or experience, it would be great if you'd share.

Thanks

[JeffWard]

450 Bush brass can be made from .284 brass, but it's a bitch, and .284 brass isn't plentiful.

If you're looking for a "bigger" bore AR-15 round, research the family of cartridges being produced by Whiskey 3 Precision, starting with the .375 Reaper. It is made from 308 brass pretty easily.

JW

[sillycon]

So far as I recall, all three are proprietary brass.

Back when I was faced with the same decision some years ago, I ended up opting for the .458. Reason being that while store-bought ammo could be had for the .50 Beo, (at the time) the .50 was limited to pistol-caliber bullets which had jacket separation and other issues at rifle velocities. The .450 was nearly impossible to find brass, bullets, parts, etc. for, which left the .458 as a bit of a "shining star" since it closely mimics the 45-70 ballistics, and uses all of those same bullets, and has/had parts availability due to Marty/Teppo, RRA, Tromix, and others being on "the bandwagon".

These days it may just come down to willingness to spend for (and deal exclusively with) AA vs. willingness to settle for an "almost-50" and having a plethora of vendors supporting it.

[savagetactical]

I've heard the 458 socom uses standard unmodified AR-15 magazines without any problems, but 50 Beowulf needs the feed lips to be bent outward a little to ensure reliable feeding. Something to consider since the industry is moving towards polymer mags that can't be bent.

[sillycon]

The .458 does in fact use standard mags; the issue with the polymer mags in the .458 is that some load combinations (such as those with hornady SST bullets) won't fit (COAL is too long) because of the front rib in the magazine. JHP's and flat-point JSP's are typically fine though.

It really is a heck of a cartridge; a 45-70 in an AR-15 is nothing to sneeze at - the proverbial 10lb of "stuff" in a 5lb sack, as it were.

[whiterussian1974]

You might be looking at creating your own proprietary cartridge if you're wanting existing bulk brass. Pick your needs, then decide upon the bullet mold to fit its ability.

If you were just going for off the shelf, I would pick .450Bush and then get bulk pricing. I always buy a case at a time. That's 1k for most cartridges, 1320rds for 7.62x39mm.