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 standard version of the large-frame VMOS™ carrier includes three steel weights, two of which can be exchanged for heavier tungsten weights. Package includes carrier and instruction sheet. Requires DPMS-pattern bolt, firing pin and cam pin.
Enhanced tunability of operating system
Guaranteed reliability of difficult configurations
Increased bearing surfaces for slower wear and longer component life
Longer cocking pad for optimal reliability
The large-frame VMOS™ carrier uses the same steel and tungsten weights as GEN 2 Silent Captured Spring units. Only the forward two masses are reconfigurable. The rear-most steel mass cannot be exchanged. This carrier should not be run stripped (i.e., without any masses).
This carrier will not cycle with a standard buffer retainer plunger installed and should be used only with a Silent Captured Spring.
Because the JP Law Tactical Folder Silent Captured Springs require use of a buffer retainer plunger to work, they are also not compatible with this VMOS™ bolt carrier.