Picking the CMMG DISSENT Br4 is easy, but choosing the right caliber to add to your safe will be a challenge. The 14.5" models have the ZEROED SVD muzzle brake that is pinned & welded to the muzzle, bringing the barrel's overall length to 16.1" which means no NFA tax stamp is needed as well as being in one of the best-looking rifles in its class. The 22 ARC Models already have a 16.1" barrel and do not have a pin & welded muzzle brake.FeaturesAdjustable Gas BlockCompact Action-Direct ImpingementCMMG Zeroed Muzzle BrakeMagpul 870 ButtstockCMMG Zeroed Drop in Single Stage TriggerReverse Cross Bolt Safety Selector2 Magazines Included