What does P&W mean?

Pinned & welded

P&W stands for Pinned and Welded, referring to how the muzzle device is attached to the barrel. Having a pinned and welded muzzle device serves as a permanently attached muzzle device (usually resulting in barrel damage if attempting to be removed) per ATF standards. This is done so that manufacturers can have barrels that are shorter than 16” and including a pinned and welded muzzle device takes the overall length to greater than 16”. With CMMG products, this is done specifically with our 14.3” and 14.5” barrels.