[SAR Review] JP Enterprises LRI-20: The Utmost Refinement of the AR-10 Platform

By: Oleg Volk –

“John Paul” founded JP Enterprises in 1991 after 13 years of running a specialty store and gunsmithing business. Since then, he, and later his son, have created progressively more refined variants of AR-15 and AR-10 designs. Since 1955, these two Stoner rifles have undergone numerous refinements. The most visible of these is the relocation of the charging handle from inside the “carry handle” to the back of the receiver. That change enabled easier installation of optics and also kept the charging handle cool during sustained fire. Other improvements included free-floating forends, better triggers, and more robust stocks. It took JP’s genius to get the AR-10/15 platform to where it performs accurately and comfortably with sound suppressors. 

As a military weapon designed to work in stock configuration, M16s and AR-10s perform quite well. However, JP modifications resulted in significantly more useful rifles for individuals interested in suppression without over gassing, extreme accuracy, or effectively functioning with unconventional ammunition. The JP LRI-20 features the time-proven LRP-07 (Long Range Precision) lower, with LRI (Long Range Integral) upper. The word “Integral” in the LRI-20 name refers to the improved forend mounting system that promotes precise, rigid alignment with the receiver. 

The most obvious difference between a JP rifle and a standard AR-15 is the large, folding side charging handle. The standard AR-15 is difficult to use in the event of a stuck casing, providing insufficient surface area for the fingers to grasp. The JP handle, which is much wider than those of other side-chargers, provides a whole-hand grip and allows charging without breaking the cheek-weld. Its forward location makes for a more natural motion than the rear-placed standard part. From this change comes another advantage: the back of the receiver is completely enclosed. Any smoke or gas that ends up in the receiver comes out through the ejection port, not through the charging handle opening right by the shooter’s eyes. Any gas that might try to escape from the side-charging handle slot is thoughtfully blocked with a sliding cover.

Fortunately, over-gassing due to back-pressure from a sound suppressor or an aggressive muzzle brake is not a problem for JP rifles. The LRI-20 upper has an adjustable gas block that is operable with a simple hex wrench. While it doesn’t have markings for repeatable positions, an indicator line is easy to add, and the port is accessible without dismounting the forend. John Paul recommends using gas adjustments for small-scale tuning, especially for target shooting. For major changes or rough field use, he advises swapping the bolt and buffer weights.

This is where another useful feature comes in. The rifles are available with low, standard, and variable mass bolt carriers. The mass of variable carriers can be fine-tuned with steel or tungsten weights. The heaviest configuration slows down the bolt opening just enough to drop the gas pressure in suppressed configurations to ensure a clean cycle. The lightest aluminum carriers are paired up with low-mass titanium firing pins to reduce the amount of reciprocating weight in competition rifles. My sample rifle had a variable-weight carrier configured with two tungsten weights, and one steel weight for suppressed use. It also included the JP Silent Captured Spring, a required replacement of the standard AR spring and buffer. Precision-centered and polished, this combo also permits fine-tuning with steel and tungsten weights. The same part can be configured with weights and a spacer to work in an AR-10, AR-15, or a 9mm blowback rifle. Unlike Stoner’s original buffer with its characteristic “boing”, JP rifle buffers remain silent during the cycle.

This isn’t the first time I’ve used JP rifles. I’ve shot the .308 LRP-07 in 2010, and the .223 SCR-11 Rifle the following year. Setting up the LRI-20 was very straightforward: the gas required no adjustment, and zeroing with the 6-24 Meopta scope took only eight rounds of 168gr Federal Gold Medal Match. While any quality ammunition can be used to good effect, that is the recommended load. With the standard two-port muzzle brake and compensator, the .308 rifle’s recoil was reduced to sub-.223 level and muzzle rise eliminated, permitting spotting of shots through the scope at one hundred yards.

Unlike dedicated sporting guns, this rifle retains the forward assist and the dust cover. The extensively ventilated 17.5-inch forend is coupled with the nut integrated into the receiver for best stability. With the front rail attachment very near the muzzle, it gives the best possible stability on an Atlas bipod. The distance between the buttstock and the bipod is maximized, translating any rear movement into a smaller angular change for more precise aiming. For a higher volume of fire, a finned aluminum radiator can be added to the barrel. The standard JP MK III Handguard System uses 10-32 screws for adding rails and other accessories where needed, leaving the surface streamlined for easy handling.

The JP LRI-20 features a 20-inch barrel that is air-gauged and cryogenically treated for utmost consistency even when hot. 0.5 MOA is guaranteed: and I’ve seen results in the one-third MOA range with factory match ammunition. Its trigger weighs in at 3.6 lbs., but it feels significantly lighter thanks to the crisp break. Felt recoil is mild, the break is not concussive, and muzzle-rise is minimal as to permit spotting your own shots at 100 yards. In other words, I had almost the same experience with the LRI-20 as I did with the .223 SCR-11 Rifle, just while making bigger splashes on steel downrange.

A thread-on Thunder Beast  Arms Corporation titanium sound suppressor reduced the noise considerably while keeping the recoil about the same as with the brake. My point of impact shifted about 2MOA between the brake and the muffler, but accuracy was unchanged. Blowback while shooting suppressed was minimal, and no blowback at all was perceived once the gas port was closed by half of a turn. The enclosed back of the receiver is perfect for use with silencers.

My experiences with all four JP Rifles so far have proven them to be 100% reliable with or without the can; and I did not experience a single failure of any kind. With Federal Gold Match 168gr open tip bullets, the spread was around 0.5 MOA, as advertised. The same results were obtained with Hornady 168gr match and PRIME 175gr match. Plain 150gr plinking FMJ shot 1.5 MOA. Magtech 168gr match achieved 1.3MOA, same as Federal Fusion Soft Point.

The LRI-20 is also available in 6mm and 6.5mmCreedmoor, as well as 260 Remington calibers. In my experience, 6.5 Creedmoor edged out the .308 for accuracy at 0.3 MOA with factory Hornady and Federal Match ammunition. John Paul recommends handloading to the specific rifle for consistent groups at 0.5 MOA, and he has produced several informative videos on turning the gas system and the handloads to each other (see them at youtube.com/user/JPRifles). At my shooting skill level, I will take the 0.5MOA dispersion with the comfortable ergonomics and mild recoil and apply my time to learning how to calculate dope and wind better.

The JP LRI-20 rifle with PRS stock, the scope, a sling, a full magazine, and the Atlas bipod weighs around 14.5 pounds. For more on the JP LRI-20, please visit JP Enterprises.