Krebs Custom Interchangeable Muzzle System (IMS) for AK rifles is now available through their website at $90. It allows to have 16.25″ barrel length and still be able to attach different muzzle devices without significantly increasing the overall length (except when used with suppressors). The system consists of a base device which is a four prong flash hider, and a closed-end “birdcage” compensator. The base flash hider must be pinned on the barrel to extend 14.5″ barrel length to 16.25″. It also features external threads and a built-in AK-style plunger detent to host the compensator and other muzzle devices.
IMS also works with Liberty Suppressors A-Kaotic silencers. All components of the system are made of 4140 steel heat treated to 40 Rockwell hardness. All the parts have black oxide finish. The overall length of the base flash hider is 2.9″ extending only 1.95″ over the muzzle. The birdcage compensator adds only 0.225″ to the length of the system. The internal thread pitch of the base device is metric 14×1 LH, which is normally seen on AK-47 rifles. External threads have a metric pitch of 24×1.5 RH, which in its turn is another standard AK thread pattern.
Krebs Custom will also introduce a titanium muzzle brake by the end of the year, which will work with the IMS system too. Besides that, they are designing more than 20 other IMS compatible devices and are looking to partner with other manufacturers to make even more options for the system.