Plan B A2 Flash Hider
Most shooters end up owning two muzzle devices for the same rifle. One lives on the gun. The other is whatever the suppressor needs, and swapping between them…
Most shooters end up owning two muzzle devices for the same rifle. One lives on the gun. The other is whatever the suppressor needs, and swapping between them means breaking Rocksett loose, torquing a new device on, and confirming zero all over again.
The Plan B A2 is both. Unsuppressed it works as an A2 flash hider, the pattern that has been reducing muzzle flash on service rifles for forty years. Add the can and the same device is already your mount. Nothing comes off the barrel.
How Plan B mounts
Behind the threads sits a precision taper. Your suppressor threads down until that taper seats, and from there the taper does the locating: it pulls the can concentric with the bore and it seals the joint.
Your zero survives the swap. Threads alone hold a suppressor loosely. A seated taper puts it in the same place every single time, so moving the can between hosts stops costing you a range trip.
Carbon stays out of the threads. The taper seals where gas would otherwise work in. That is the difference between a suppressor you unthread by hand after a long weekend and one that needs heat and a strap wrench.
Nothing extra in the gas path. No collar, no spring, no locking lever to carbon up or wear loose. Fewer parts in the hottest place on the rifle.
Which thread do you need?
We stock this device in 1/2x28 and 5/8x24. Bore diameter drives the choice.
| 1/2x28 | The .22-caliber standard. 5.56 NATO and .223 Remington, .22 LR, .22 WMR, .17 HMR. Many 9mm barrels use it too, though plenty of others are cut 1/2x36. |
|---|---|
| 5/8x24 | The .30-caliber standard. .308 Winchester and 7.62x51, 300 Blackout, 6.5 Creedmoor, 6mm ARC, 6.8 SPC, .243 Winchester, .30-06, .300 Win Mag, and 7.62x39 on AR-pattern barrels. |
The thread follows the barrel, not the cartridge. Treat the table as a starting point and confirm against your barrel maker's specification.
.350 Legend is the cartridge that catches people out. It sits between the two standards and the industry never settled it. Ruger ships American rifles in 1/2x28 while other makers thread the same cartridge 5/8x24. Check that one before you order rather than after.
Specifications
| Thread | 1/2x28 or 5/8x24 |
| Overall length | 1.850" |
| Protrusion | .710" |
| Material | 17-4 stainless steel |
| Finish | Nitride |
| Weight | 2.5 oz |
| Wrench flats | 13/16", milled rear |
Installation
Use Rocksett and torque to 20–25 ft-lbs on the milled rear flats. The taper indexes the suppressor, so this device does not need timing or a crush washer.
Worth knowing
Mounting a suppressor to this device requires a Plan B suppressor hub. If your can has a 1.375x24 HUB rear cap, our Plan B HUB Mount is the piece that connects the two.
This is a Plan B interface. It will not mount ASR, KeyMo, or tri-lug suppressors.
Some suppressor manufacturers limit warranty coverage when you run a third-party muzzle device. Check yours before you commit.
