This one has me thinking I need to get into the AR game. Now the only question is buy a complete rifle or build one.
Many ways to skin that cat. You can buy a complete upper, then build the lower, or buy a complete lower, or buy the parts and assemble it yourself, as well as buy a complete rifle over the counter. Here's a link Midsouth sent me on this new cartridge:
Midsouth links to 6mm ARC