JP Enterprises VMOS Variable Mass Heavy Bolt Carrier LR-308 Stainless Steel QPQ Black

For difficult setups like suppressed rifles and exotic caliber chamberings, some degree of mass regulation is required for optimal performance. This is especially true in the absence of an adjustable gas block. Residual gas and excessive fouling can grind your rifle to a stop. One size never fits all when it comes to gas-operated rifles. The Variable Mass Operating System (VMOS) carrier ensures reliability through additional reciprocating mass but provides more custom tunability. Combined with our Silent Captured Spring, multiple masses are exchangeable to perfectly tune your operating system weight. This heavy version of the large-frame VMOS carrier includes one steel and two tungsten weights, which can be exchanged for lighter steel weights. Package includes carrier, Enhanced Gas Ring and instruction sheet. Requires DPMS-pattern bolt, firing pin and cam pin. Works best with 284263.