Two thread pitches cover almost every AR-15 and AR-10 barrel you will encounter: 1/2x28 and 5/8x24. Picking the wrong one is the most common reason a muzzle device arrives and will not thread on. Most guides stop at "check your barrel." This one explains why the two pitches exist, which calibers use which, and what actually interchanges once you know your thread. Why Two Pitc …
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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 …
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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 …
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