Description
The Armaspec Rook is a micro compensator that Armaspec describes as “slightly longer than a regular thread protector.” It is built for carry and range pistols where the shooter wants a little muzzle control without a full-size comp. It threads onto a 1/2×28 barrel and tightens with built-in wrench flats. Armaspec states “we recommend using Blue Loctite or Rocksett” to keep it from backing off; there are no shims or set screws. A 1/2×28 threaded barrel is required and not included.
Armaspec machines the Rook from stainless steel with a QPQ (nitride) black finish. The porting is described as “slotted gas ports”; Armaspec does not publish a count. Listed dimensions are 0.82 inch long and 0.74 inch wide, so it adds well under an inch to the muzzle and stays inside the width of most slides. It ships as the compensator only; thread locker is not included. Armaspec does not publish recoil spring or ammunition guidance.
Fitment: Armaspec lists the Rook by thread (1/2×28) and marks caliber as “Multi,” meaning it is a general purpose device for 9mm and smaller bores in that thread. It is not shaped to any slide, so it works on Glock, SIG, Springfield, Smith and Wesson, and other pistols with a 1/2×28 threaded barrel that has enough thread protrusion to seat the comp. It will not fit M13.5×1 LH barrels. Since it indexes on the barrel shoulder, thin-barrel micro compacts with little shoulder (Glock 43 and 48 family, P365) should be test fit before you commit; Armaspec does not address them. Any comp will change holster fit, though this one adds very little.
Specs
- Fits: 9mm pistols with a 1/2×28 threaded barrel
- Caliber: Multi (9mm and smaller, 1/2×28 thread)
- Thread pitch: 1/2×28
- Ports: Slotted gas ports (count not published)
- Length added: 0.82 inch (0.74 inch wide)
- Material: Stainless steel
- Finish: QPQ black
- Threaded barrel required: yes
- Includes: Compensator only (thread locker recommended, not included)
- Manufacturer part number: ARM4511-BLK
- UPC: 810048493852
Who it’s for
Shooters who want the least expensive way to put something more useful than a thread protector on a threaded 9mm barrel, for carry, PCSL 2-Gun, Tactical Games, or USPSA Limited Optics and Open.
Who should skip it
If you want a micro comp that installs hand tight without thread locker, the True Precision Cobra uses a tension lock O-ring. If you want a comp cut to match your slide, the Faxon EXOS or Strike Industries Mass Driver are the options in this batch for Glock, SIG, and Smith and Wesson. USPSA Production and Carry Optics do not allow compensators or threaded barrels with a device attached, and IDPA SSP and CO do not allow comps; IDPA CCP and ESP rules vary, so check the rulebook.
