Pick the wrong AR-15 buffer weight and the rifle tells on you: brass thrown three feet forward, a bolt that short-strokes on cheap ammo, or a snappy recoil impulse that fights your follow-up shots. Buffer weight is the cheapest, most reversible way to tune how an AR runs, but the "use the heaviest buffer that still cycles reliably" rule everyone repeats only works once you unde …
read more

If you already own a 5.56 AR-15 and you're eyeing 300 Blackout, the real question is what you can keep and what you have to replace. The answer is cleaner than most forum threads make it: your bolt carrier group, lower, buffer, and magazines all carry over. Only the barrel and gas system change. Everything else about a 300 BLK upper is identical to your 5.56 rifle. The short an …
read more

Barrel profile is the contour of an AR-15 barrel — the amount of steel left along its length — and it decides how much your rifle weighs, how fast it heats up, and where it balances. It is a separate spec from barrel length. A 16-inch barrel can weigh anywhere from about 1.5 pounds to over 2.5 pounds depending on its profile, and that difference is felt every time y …
read more