One of these things is not like the others....

Click the pictures to embiggen!

One of those muzzles is more than twice the size of the other. That is my new AR-15 upper from Rock River Arms, chambered in .458 SOCOM. You may recall I posted on Nov 2 my thought process on choosing this round over the .50 Beowulf, the other contender to scratch my "Big Bore" itch. After an 11-week wait, it was delivered.

I've not had a chance to haul this to the range, but once I do y'all be the first to know. However, my initial impressions are favorable. It came with a single rail gas block and a free float aluminum handguard, as well as an oversized A2 style flash hider. Mounted on an A2-stocked lower, the gun is a little muzzle heavy, but not as much so as my 24" stainless barreled AR. The barrel looks like a 3/4" water pipe - very solid and impressive.

I did purchase a couple of boxes of commercial ammo to get some immediate gratification before I start cooking up my own. Loading recipes for this caliber are few and far between despite the vast selection of projectiles available. I've gathered a few from the internets, but will have to be careful about working up a good load. The commercial stuff should help by serving as a baseline.

I've already got a nice selection of components in hand, including a couple hundred of the the 500 gr Barnes TSX-DG solid shown above, in case I need to put down a charging cape buffalo in southeastern Pennsylvania. I've also got a few 300, 325, and 350 grain hollow points and "Flex-Tip" on hand or en-route to play with. I fully expect this to be a blast to shoot!