One Horse OH-15 AR-15 5.56 NATO 10.5" 30rd Pistol

One Horse assembles the OH-15 as a complete AR pistol rather than a parts pile, and this one is set up in 5.56 NATO behind a 10.5" medium profile barrel. That length is the sweet spot for a carbine gas system in 5.56: short enough to clear doorways and vehicle interiors, long enough that the round still does useful work downrange. The muzzle is threaded 1/2x28 and wears an A2 device, so a brake or a suppressor mount goes on without a trip to a gunsmith. Twist is 1:8, which stabilizes everything from light varmint bullets up through heavy 77 grain match loads.

A 9.25" M-LOK handguard covers most of the barrel and puts rail space exactly where your hand lands instead of everywhere at once. Controls are standard AR, the charging handle and buffer tube are mil spec, and the grip is a plain A2, which means the aftermarket parts already in your box drop straight in. A KAK brace rides on the back and one 30 round magazine is included. For a home defense gun or something that lives behind the seat, a braced 5.56 at this length is a hard configuration to argue with.