All Posts

Candela tell you how far the beam throws and how well it punches through darkness, glare, and barriers. For a weapon light, candela is usually the more important number, even though lumens is the one splashed across the box.

Any mount labeled "Scout-compatible" or "Scout pattern" bolts to those two holes. Surefire introduced this footprint in 2006, and because it works so well, the rest of the industry adopted it rather than inventing competing standards.

To figure out which one you have without disassembling anything, measure from the front of your upper receiver to the front edge of your gas block. Roughly 7 inches is carbine, roughly 9 inches is mid-length, roughly 12 inches is rifle, and roughly 4 inches is pistol.

For every other common barrel length, the answer is just as specific. There's no universal "go as long as you can" rule, and there's no aesthetic choice that overrides the two hard limits: longer than your gas system, shorter than your barrel.

The HUB standard exists because the pre-HUB suppressor market was a compatibility nightmare. SilencerCo had ASR. AAC had 51T. Surefire had SOCOM. Dead Air had KeyMo. Each brand's suppressors only worked with that brand's muzzle devices and mounts. Buying a new can locked you into an entire ecosystem.

There's also a third option most buying guides skip: taper-shoulder QD mounts (Thunder Beast CB, Griffin Taper, Dead Air KeyMount). These bridge the gap by giving you direct-thread-level accuracy with QD-style mounting speed.

It eliminates barrel shadow at close range, puts the tail-cap switch directly under your support thumb in a C-clamp grip, sits low enough to avoid snagging on doorframes and gear, and doesn't compete with optics or iron sights for top-rail real estate.

That's the short version. This is a different question from "M-LOK vs Picatinny handguard," which has been settled by SOCOM testing in M-LOK's favor. The light mount question is narrower: assuming your handguard has both M-LOK slots and a Picatinny top rail (the most common modern configuration), which mounting style should the light itself use?

That said, the "best" position changes based on your grip style, your switch type (tail cap, pressure pad, or toggle), what else is on your rail, and whether you're left or right-handed. This blog will break down every common position, explain what each one does well and where it fails, and give you a decision matrix you can match against your own build.

Drop-in handguards still win on one thing: price and install time. If you're upgrading a budget carbine, want a 10-minute swap, and don't care about mounting accessories or shooting from a supported position, a drop-in handguard is a fine choice.

Pick Picatinny only when you specifically need a rail surface for optic mounting on top of the handguard or for legacy accessories. Pick KeyMod only if you already own a stash of KeyMod attachments and don't want to re-buy them.

If you're staring at handguard options and wondering what size handguard do I need for your AR-15, the short answer is this: your handguard must be longer than your gas system and shorter than your barrel.