Please note that though the ABC/R v3's upper paddle is angled and tapered, and we have tested it on upper receivers with a small, oval shaped bolt catch paddle cutout, such as found on DMPS's LR308 upper receiver, the upper corners of ABC/R v3 7.62mm may come in contact with receivers and mar it in two small places inside the cutout.

These are cosmetic only, they don't affect the functionality of the bolt catch.  For receivers with a generous bolt catch paddle cutout, such as Rainier Arms, Mega, F4 Defense, etc. there is ample clearance for ABC/R v2, 7.62mm.

For more info on the dimpled ABC/R-AA, please follow this link ABC/R-AA

Please note the ABC/R was not designed for use on 9mm receivers that use Colt 9mm magazines which require a Colt 9mm bolt catch.

Incompatibilities:
KAC SR25
Armalite AR10B