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General | Media

Full Mass Operating System

For police duty or any application where absolute reliability is the main criteria, our 416 stainless steel Full Mass Operating System (FMOS™) carrier design is the top of the line. The JPBC-2 has every strength an operator expects from a Mil-spec. carrier matched up with improvements born from decades of shooting and engineering experience. Heavier than a standard .308 carrier, our large-frame JPBC-5 is the solution for rifle needing more mass regulation.

Designed with extended forward assist serrations and a dust cover notch, our FMOS™ carriers also feature a 100% increase in bearing surface for smoother operation, improved alignment and lower wear in the upper receiver as well as a longer Mil-spec. cocking pad for optimal reliability.

Just as critical as the design is the robust finishing process of the FMOS™ carrier, which receives a roller-burnish of its bore for frictionless operation, eliminating the peeling chrome common to standard Mil-spec carriers. Then, the exterior bearing surfaces are polished before the carrier undergoes our state-of-the-art, multi-vendor QPQ (Quench-Polish-Quench) process that results in a rock-hard surface with remarkable natural lubricity. This is hands-down the best designed and highest quality general purpose carrier on the market, and when properly lubricated, a JP operating system will make your rifle feel like it's cycling on ball bearings.

Full Mass Operating System | Small Frame
JPBC-2JP FMOS™ Bolt Carrier
   Small-Frame (.223)
   Stainless Steel
   QPQ Black Finish
JPBC-2 BCGJP FMOS™ Carrier Group with JP EnhancedBolt
  Caliber Selectable
  Stainless Steel
  QPQ Black Finish

Full Mass Operating System | Large Frame
JPBC-5JP FMOS™ Bolt Carrier
   Large-Frame (.308)
   Stainless Steel
   QPQ Black Finish
JPBC-5 BCGJP FMOS™ Carrier Group with JP EnhancedBolt
   .308 | .308 HP
   Stainless Steel
   QPQ Black Finish

Full Auto FMOS Carrier

Drawn from the same design as our the semi-auto JPBC-2, our JPBC-16 carrier is the full-auto version of our FMOS for use in select-fire M16 weapons and includes all the necessary features for a full-auto configuration. Like all our black carriers, the JPBC-16 undergoes our multi-step QPQ (Quench-Polish-Quench) finish for a rock-hard surface with high natural lubricity.

While this carrier is the perfect fit for full-auto platform, it is unadvisable to use any full-auto components in a semi-auto AR-15. Be aware that if you happen to have an unexplained "double" (more than one round firing with one press of the trigger), you could be prosecuted for manufacturing and possessing an illegal weapon.

Full Mass Operating System | Full Auto


Can I buy the JPBC-16?

There is nothing in the law that prohibits us selling the JPBC-16 to you, but the BATF is wary of civilian ownership for such components. If you were ever to have your rifle double for any reason under the wring circumstances, you could be prosecuting for owning a machine gun in you have any select-fire components installed. The law is ambiguous but easy to steer clear of. For must users, the JPBC-2 is completely serviceable. These carriers are identical except for the full-auto cutout.

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