CRMD vs. OBMD : how and when to use each
The JK Armament 195 series of 12 gauge shotgun suppressors has two primary mounting options: CRMD and OBMD. CRMD stands for choke replacement muzzle device. OBMD stands for over barrel muzzle device.
If you are looking to suppress a shotgun that uses interchangeable chokes, go with a CRMD. Your existing chokes screw into the inside of your barrel, and this is how you control your shot pattern constriction level. Our CRMD will simply screw into your barrel in place of your choke tube and will then act as a quick attach muzzle device onto which your JK 195 suppressor attaches.
If you own a shotgun that isn’t threaded for choke tubes, which is the majority of tactical and self-defense style shotguns, we recommend using our OBMD. This likely means you’ll have to get your shotgun’s barrel threaded, which is a service we offer here at JK. An OBMD installed on external threads offers a shorter mounting system compared to the CRMD, and it’s also more robust.
How to use ‘em:
In either case, since it’s the Choke Cap at the very muzzle end of the JK 195 suppressor that controls shot pattern constriction, you’ll have full, rapidly-swappable choke levels available by simply exchanging Choke Caps. As its primary function is to act as a quick attach mount for your 195 suppressor, your CRMD or OBMD should remain “permanently” installed on your barrel.
In fact, unless you’re planning on moving one CRMD/OBMD across multiple shotguns (it’s far faster and easier to have one pre-installed on each of your guns, instead!), we’d recommend using a removable thread locker to lock it in place.