How to Time a Muzzle Brake (and When You Don't Have To)

Timing a muzzle brake means adding shims or a crush washer between the brake and the barrel so that it stops tight with its ports at the intended clock position. The RRD™ 360HD does not involve that, because its spec sheet lists "Requires Timing?: No." Thread, hand, and FaceMount or shoulder indexing are still specific to each rifle, and suppressor alignment is a property of the installed device and rifle.

Parts in this post

• 
  360HD Plan B Taper Mount
• 
  360HD KeyMicro®
• 
  360HD X37 HUB Mount

Timing a muzzle brake with shims

A directional brake has to stop at a set orientation. Shims or crush washers between the device and the barrel set where the device stops. A device that stops at the wrong clock position points its ports the wrong way.

Timing a muzzle brake with a crush washer

A crush washer compresses as the device is tightened, so the device can stop at the intended clock position. Crush washers are generally single-use.

Muzzle brake timing without shims

The 360HD spec table says "Requires Timing?: No." It comes in two indexing types:

• Shoulder devices "index against the shoulder of the barrel."
• FaceMount devices "index against the face of the muzzle of the barrel."

FaceMount matters on AKs. Many AK barrels have no true shoulder to seat against, so the device seats on the muzzle face instead.

The 360HD table still lists a FaceMount shim for some models. Our page states: "If using shims with Facemount devices, you must use an alignment rod to ensure the Facemount shims do not make contact with the projectile exiting the muzzle."

WARNING: Have a qualified gunsmith install this product and verify suppressor alignment with an alignment rod before firing. Improper installation or misalignment can damage the device or suppressor and cause serious injury or death.

KeyMo muzzle brakes and timing

The 360HD KeyMount versions work with any KeyMo-equipped suppressor or accessory and list no timing. They are 17-4 PH stainless steel with a satin QPQ black nitride finish and have three sacrificial baffles.

Why the 360HD on an M14x1 left-hand AK?

On M14x1 left-hand AKs, the 360HD line, including the 360HD Micro, needs no timing, is 17-4 PH stainless with QPQ black nitride, and the KeyMount versions take a KeyMo suppressor.

WASR-10 thread pitch: what thread and hand does my AK have?

Thread hand: M14x1 and M26x1.5 are left-hand; M24x1.5 is right-hand. The M85 uses the M26x1.5 LH device with the bushing (360HD-26F-TM+98042A031), which fits the M85 with conditions.

What has to match for a 360HD to fit?

1. Thread: pitch, hand and FaceMount or shoulder indexing are specific to each rifle. A thread match alone is never proof of fit.
2. Caliber: each device has a stated caliber range. For example, the -45 models are listed for .40 to .458.
3. Suppressor (AK): alignment is a property of the installed rifle and device.

FAQ

Does the 360HD need timing?

No. Our spec table lists "Requires Timing?: No."

What is a FaceMount?

A device that indexes against the muzzle face instead of a barrel shoulder.

Is the WASR thread left-hand?

Yes. It is M14x1 LH.

Does suppressor use on an AK depend on alignment?

Yes. Alignment is a property of the installed rifle and device.