AR9
Any of the Safetys or Complete Kits (excluding the LaRue MBT) that we sell will work in an AR15 chambered in 9mm.
The rear of the BCG will need to measure 1.57" in order to work correctly.
We advise against using a Foxtrot Mike FM9 BCG with a Super Safety due to a frequent "failure to fire" problem when used in conjunction with a Super Safety. We've been told that it is a firing pin design issue by sources more knowledgable than us, but we have no personal experience with the FM9 BCGs.
AR9 specific issues:
On AR9s, if the BCGs internal weight protrudes past the lower lip of the BCG, you’ll need to remove the weight and trim it to make room for the lever. If the weight extends up and over the lever, you may experience binding as the bolt is nearly closed. This is because the lever and the weight are making contact, the weight will BREAK THE LEVER if this area is not trimmed. Again, you will need to remove the weight and trim it to make room for the lever to move freely. Most of the AR9 internal weights are held in place with a roll pin – using a hammer and punch, knock out the roll pin and remove the weight. Reinstallation is the opposite once you have trimmed the weight.
