JP Enhanced Bolt Carrier Completion Kit for AR-15/M4 Rifles and Carbines
This Enhanced Bolt Assembly for AR-style AR-15/M4/M16 rifles includes Bolt Assembly with Extractor. This new high performance bolt assembly is made from SAE 9310 steel which is extremely durable and has at least ten times the life expectancy of a mil-spec 8620 steel bolt. This bolt has mil-spec dimensions so it is compatible with any AR-15 bolt carrier and uses a mil-spec sized extractor.
Standard Mil-spec 8620 bolts have a number of Achilles heels, so to speak. The result is a life expectancy of 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. Other problems include cracking at the cam pin hole and week extractor spring tension. Piston driven rifles can even have increased stress on the bolt from the operating system.
The material used in standard bolts is also not the best choice by todays standards. But if you remember that old story that explains why “Mil-spec never dies”, well that applies here also. They make them this way because they’ve always made them this way. Our new bolt is made from SAE 9310 high grade steel. With this material, an extremely hard surface with a tough ductile core resistant to structural failure is provided resulting in a ten fold improvement in life expectancy. This has been observed in actual full auto endurance torture tests. SAE 9310 is the same type of steel used in the transmission gears of formula one race cars. The high load application of a bolt assembly is the ideal application for this state of the art material.
Additionally, many other fine points have been addressed such as incorporating radiuses in all the traditional 90 degree corners of the locking lug areas. This further enhances the ability of the bolt to handle high loads over a much longer life span. Made to meet JP's rigid quality standards. We highly recommend this bolt as a compliment to JP bolt carriers or any quality AR-15 rifle system.
The Bolt Carrier Completion Kit includes the JP Enhanced Bolt Assembly, plus a cam pin, a firing pin and a firing pin retaining pin to complete a bolt carrier assembly in any .223/5.56mm AR-15 type rifle.
*Designed for .223/5.56 NATO rifles
*In photo the black bolt is a standard bolt for comparison