JP .308 One Piece Enhanced Gas Ring JP Enterprises AR10 Mcfarland
After testing numerous minute grind callouts, the final JP Enhanced Gas Rings spec is the perfect balance of a solid gas seal with a very low-friction relationship between rings and bolt carrier. Reducing the resistance between these components directly results in an overall increase in the rifle's reliability while the rings utilize the cycling action itself to scrape the walls of the carrier, helping shed fowling with every shot. One JP enhanced ring replaces the 3 standard bolt rings that can misalign on a bolt head. Upgrading with the JP ring will eliminate this potential cause of failure.
The JPEGR-308 utilizes a one-piece design similar to the Mcfarland rings. Unlike the Mcfarland rings, though, our precision-ground gas rings are engineered to precisely suit DPMS-patterned carrier group components such as our own JP EnhancedBolt™.
How It's Supposed To Work
Upon firing, as the pressure of the gas generated by the burning propellant drives the projectile down the barrel and past the gas port, a small quantity of the gas is bled off through the gas port, gas tube, and bolt carrier key into the cylindrical section in the bolt carrier where it expands and drives the bolt carrier rearward. During the first rearward travel of the carrier, the bolt is rotated by the cam pin acted on by the bolt carrier cam slot. This rotation disengages the bolt lugs from the barrel extension lugs and so the bolt is unlocked. The carrier then continues rearward with the unlocked bolt. At this point, the gas used to drive the bolt carrier rearward is allowed to bleed out through two holes on the right of the bolt carrier.
In order to install the rings on the bolt, they must be split and thus a "gap" on each ring is unavoidable. The problem arises because these gaps can become aligned, and cause too much gas to escape too early in the cycle. This can result in short-stroking and possibly jamming the rifle, so manuals and instructors enforce the proper alignment of the rings when reassembling the AR-15 rifle.
A one-piece gas rings solves the problem of "aligned" gaps by eliminating the gaps. As a one-piece helical ring, you are guaranteed to never have the problem with the gaps.
The 3 individual rings can be removed one at a time starting with the rearmost ring first. Lift one end of the open ring up and over the edge of the ring groove (towards the rear of the bolt) and then work the other end over. Repeat this for the remaining two rings, and you should be able to remove them without damage. As a single piece of metal, the JP ring is wound onto the groove on the bolt's rear. Start one end over the edge, and then work the remainder of the ring over that edge; the easiest way to accomplish this is without trying to turn the ring itself.