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JP High Performance Operating System Components


JP Low Mass Operating System

We have our own purpose designed operating systems. For the no-compromise competition rifle, the LMOS™ offers the most significant improvement in the felt impulse of the rifle as compared to any modification other than the addition of a compensator. The complete system consists of our low mass bolt carrier and lightweight buffer conversion kit. By reducing the reciprocating mass, the overall impulse as felt by the shooter is further reduced, and bolt velocity is increased without significantly affecting reliability. JP LMOS™ equipped rifles have virtually no reciprocating mass feel.

Reliability with these parts is excellent for competition use. We've been using this system for three years without a malfunction at a match. Most shooters that use and maintain this operating system feel that it is a great performance improvement. Some shooters have even reported fewer unexplained flyers in their groups with the JP LMOS™ system.


Left: JPBC-3 SP Polished Stainless Low Mass Carrier.
Middle: JPLMB Low Mass Buffer System.
Right: JPBC-3 Stainless Low Mass Carrier with new QPQ black hard coat treatment.

The JP Low Mass Carrier works out nicely in the new type of civilian machined receivers like ours and the DPMS High and Low Rider series that don’t have a forward assist. Although it doesn’t have the forward assist serrations, it functions in military type receivers. It just won’t allow the use of forward assist on the receiver. Dust cover functions normally.

You may be wondering why our stainless carriers appear black. This is due to a new state of the art surface finish for stainless called QPQ (Quench, Polish, Quench). This is a five-step process resulting in a rock hard surface with natural lubricity. Some want the bright polished look and that is available on the JPBC-3 Low Mass carrier, but not the JPBC-2 tactical carrier.

The JP LRP-07 has our large format AR-10 type Low Mass carrier. The JPBC-4 AR-10 low mass stainless bolt carrier is also finished in black QPQ hard coat for superior wear and natural lubricity. The JPBC-4 will also improve the sight recovery on the DPMS LR-308 or the Armalite AR10. However, it must be used with a DPMS LR-308 bolt assembly, firing pin, cam pin and firing pin retainer.

Do not attempt to use the JPBC-4 with the Armalite bolt assembly, firing pin or cam pin. Unlike the AR-15/M16 platform on which just about everything is cross compatible, each AR-10 type rifle such as the JP LRP-07, DPMS LR-308, Armalite AR-10, Knights SR-25 or Rock River AR-10 is inherently different with only limited cross compatibility of components. Always check compatibility anytime you order aftermarket accessories for AR-10 type rifles.

JP Full Mass Operating System

JPBC-2 Stainless Full Mass Carrier with new QPQ black hard coat treatment.

For police tactical duty or any application where absolute reliability is the main criteria, we have our FMOS™ or Full Mass Operating System with 416 stainless steel special design carrier that includes forward assist serrations and a dust cover notch. The bore of the JP stainless carriers has a roller burnished finish for frictionless operation with no chance of peeling chrome as in standard mil-spec carriers. The exterior bearing surfaces are also polished so that, when properly lubricated, both systems make your rifle feel like it was cycling on ball bearings.

Both the JPBC-2 and the JPBC-3 feature a 100% increase in bearing surface for smoother operation and improved alignment and lower wear in the upper receiver. Both are AR-15 semi auto configuration in the rear with the mil-spec longer cocking pad in the front for best reliability. This is hands-down the best designed and highest quality general purpose carrier on the market. Sold as carrier with installed key.

Also available is the JPBC-16 version for select-fire M-16 weapons. This model is indentical to your standard Full Mass carrier but includes the necessary features for function with an M-16 full auto configuration.

Be aware that it is unadvisable to use any full auto components in an AR-15 semi-auto rifle. 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.

JP EnhancedBolt™

9310 Bolt assembly with standard extractor. Available for .223 and .308 (DPMS LR-308 application).


To satisfy customer requests, we now offer the new JP EnhancedBolt™ with great life expectancy while utilizing a standard configuration extractor.

The truth is, the standard Mil-spec C-158 (Carpenter 158) bolt has a number of factors limiting its performance, not the least of which is that the life expectancy of such bolts is only about 6,000 rounds. In fact, standard bolts will start to show stress cracks on the locking lugs adjacent to the extractor cut after only 3,000 rounds. Cracking at the cam pin hole and weak extractor spring tension only add to the problems of the Mil-spec bolt.


Typical bolt failure mode next to extractor cut.

The material used in these standard bolts is also not the best choice by today's standards, but if you remember the old story that explains why “Mil-spec never dies,” that applies here as well; they make them this way because they’ve always made them this way.

The latest edition JP EnhancedBolt™ is made from SAE 9310 high-grade steel. This material makes for an extremely hard surface with a tough, ductile core resistant to structural failure and a life expectancy far exceeding Mil-spec C-158 bolts. SAE 9310 is the same type of steel used in the transmission gears of Formula One racecars, and the high-load application of a bolt assembly is ideal for this state-of-the-art material; the results of actual full-auto endurance torture tests prove it.

The design of the JP EnhancedBolt™ addresses many other fine points, the most important of which is the utilization of a standard configuration extractor. Most users want the ability to replace extractors and other parts with commonly available Mil-spec parts instead of being dependent on proprietary parts that can be difficult to acquire. Therefore, this new bolt will accept standard extractors, pins and springs.

The JP EnhancedBolt™ will now be standard equipment on all JP .223 and .308 rifles and uppers, and we highly recommend it as a complement to your JP High Performance Bolt Carriers or any rifle system. The .223 version of the bolt is compatible with any AR-15 platform using a Mil-spec bolt carrier and subcomponents. The .308 version is compatible with the JP LRP-07 and the DPMS LR-308 platforms (or clones thereof) only and cannot be used to replace bolts in the Armalite AR-10 platform (or clones thereof).


JP EnhancedBolt™ on left as compared to a Mil-spec variety bolt on right.

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JP Bolt Carriers
JPBC-2JP Full Mass Stainless Steel Bolt Carrier (FMOS)$225.95
JPBC-3JP Low Mass Stainless Steel Bolt Carrier (LMOS)$225.95
JPBC-3SPJP Low Mass Polished Stainless Steel Bolt Carrier (LMOS)$225.95
JPBC-2A-6.5GFull Mass .223 Stainless Bolt Carrier Assembly with 6.5 Grendel JP EnhancedBolt™ Completion Group (FMOS)$384.95
JPBC-3A-6.5GLow Mass .223 Stainless Bolt Carrier Assembly with 6.5 Grendel JP EnhancedBolt™ Completion Group (LMOS)$384.95
JPBC-3SPA-6.5GLow Mass .223 Polished Stainless Bolt Carrier Assembly with 6.5 Grendel JP EnhancedBolt™ Completion Group (LMOS)$384.95
JPBC-4JP .308 Low Mass Stainless Steel Bolt Carrier (LMOS)$269.95
JPBC-4SPJP .308 Low Mass Polished Stainless Steel Bolt Carrier (LMOS)$269.95
JPBC-2AFull Mass .223 Stainless Bolt Carrier Assembly with JPEB-223 JP EnhancedBolt™ Completion Group (FMOS)$369.95
JPBC-3ALow Mass .223 Stainless Bolt Carrier Assembly with .223 JP EnhancedBolt™ Completion Group (LMOS)$369.95
JPBC-3SPALow Mass .223 Polished Stainless Bolt Carrier Assembly with .223 JP EnhancedBolt™ Completion Group (LMOS)$369.95
JPBC-4ALow Mass .308 Stainless Bolt Carrier Assembly with JPEB-308 JP EnhancedBolt™ Completion Group (LMOS)$483.95
JPBC-4SPALow Mass .308 Polished Stainless Bolt Carrier Assembly with JPEB-308 JP EnhancedBolt™ Completion Group (LMOS)$483.95
JPBC-16JP Full Mass Stainless Steel Bolt Carrier for M16-type Select Fire Rifles (FMOS)

All NFA Rules Apply
$269.95
JPBC-16AFull Mass .223 Stainless Bolt Carrier Assembly for M16-type Select Fire Rifles with JPEB-223 JP EnhancedBolt™ Completion Group (FMOS)

All NFA Rules Apply
$369.95
JPEB-223JP EnhancedBolt™ Assembly
Caliber: .223/5.56
Finish: Nickel boron
$124.95
JPEB-223MPJP EnhancedBolt™ assembly
Caliber: .223/5.56 caliber
Finish: Mag. phosphate
$124.95
STD.223/5.56Mil-spec .223/.204 Bolt Assembly$43.95
JPEB-6.5GJP EnhancedBolt™ Assembly
Caliber: 6.5 Grendel
Finish: Nickel boron
$139.95
JPEB-308MPJP EnhancedBolt™ assembly
Caliber: .308 Win. caliber
Finish: Mag. phosphate
$174.95
JPEB-308HPJP High Pressure EnhancedBolt™ assembly
Caliber: .308 Win. caliber
Finish: Mag. phosphate
$249.95
JPBC-EB223JP EnhancedBolt™ Assembly Completion Group
Caliber: .223/5.56
Finish: Nickel boron
$144.95
JPBC-EB6.5GJP EnhancedBolt™ Assembly Completion Group
Caliber: 6.5 Grendel
Finish: Nickel boron
$154.95
JPBC-EB308-MPJP EnhancedBolt™ Assembly Completion Group
Caliber: .308 Win.
Finish: Mag. phosphate
$224.95
AA6.5G BOLTAlexander Arms® bolt refined and engineered for 6.5 Grendel$69.00
JPBC-BA5.56Mil-spec Bolt Carrier Completion Kit$51.95
BC-PINS-223Bolt Carrier Pin Package
Small Frame
$19.95
BC-PINS-308Bolt Carrier Pin Package
Large Frame
$39.95
JPEB-308EXJP Enhanced .308 Extractor for DPMS-pattern Bolt Assemblies$59.95
JPFRKIT-223JP Field Repair Kit, .223$59.95
JPFRKIT-308JP Field Repair Kit, .308$99.95
JPEGR-223.223 Enhanced Gas Ring$9.95
JPEGR-308.308 Enhanced Gas Ring$9.95
JPLMBJP Low Mass Buffer
for AR-15-type rifles
$59.95
JPS-OSCCustom Centerless Ground and Polished Operating Spring
Platform: Small-Frame
Length: Carbine Length
$19.95
JPS-OSRCustom Centerless Ground and Polished Operating Spring
Platform: Small-Frame
Length: Rifle Length
$19.95
JPS-OSC.308Custom Centerless Ground and Polished Operating Spring
Platform: Large-Frame
Length: Carbine Length
$22.95
JPS-OSR.308Custom Centerless Ground and Polished Operating Spring
Platform: Large-Frame
Length: Rifle Length
$22.95

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