Review: JP Enterprises JP5 Rifle

David Luttrell3 days ago

0 0 7 minutes read

JP Enterprises (JPE) is no stranger to AR-pattern 9mm firearms. Besides the PCC GMR-15 models, the company also offers the unique JP5 pistol-caliber carbine. This carbine is best described as the marriage between the well-known roller-delayed blowback action of the HK MP5 and the more practical format of an AR-15. In order to pull this concept from abstraction into reality, the engineering team at JPE designed a proprietary AR-pattern upper / lower receiver set along with a unique bolt-carrier that feeds from 9mm Glock magazines. The end-result is one of the most reliable and smooth-shooting 9mm AR-style pistol caliber carbines (PCCs) on the market today.

JPE’s firearms are not inexpensive. They’re premium 9mm PCC carbines that are typically built in small batches or can be customized and built to order. The silver lining is that these carbines aren’t limited to just a single configuration, so end-users can choose different rifle or pistol builds, barrel lengths, handguard and receiver sets according to their needs. Likewise, JP Enterprises offers different “core” builds that cater to different types of shooting styles or competitive disciplines. Our specimen is a full-size JP5 carbine built around a 14.5-inch stainless steel barrel, a pinned and welded JP Enterprises Vertical Port Compensator and the signature JP Enterprises Mk. III 12.5-inch handguard.

The Roller-Lock Action

The impetus for the JP5’s MP5-inspired action is that the 9mm cartridge just doesn’t generate high enough pressures to warrant a gas-operated action. This is why most 9mm semi-automatic PCCs use some form of blowback action. However, the typical AR-pattern straight-blowback action tends to feel clunky and has a different recoil impulse compared to rifle-caliber AR-15s. Roller-delayed actions, which date back to pre-WW2 Germany, use a pair of symmetrical rollers that cam into recesses behind the breech to lock the bolt in place. After the shot is fired, these cylindrical rollers delay the action from immediately jolting back, which skips the need for heavy buffer systems. The result is a smoother, more pleasant recoil impulse. This ingenious mechanism provides for extreme reliability, even in adverse conditions. Heckler and Koch’s entire line of classic roller-lock rifles and carbines chambered in different calibers speaks to this fact. This type of reliability, along with the smoother recoil impulse (further aided by a JP Silent Capture System) makes JP5 a top choice for large volume 9mm PCC shooters.

These types of actions use fluted chambers for reliability. The flutes serve to reduce the surface area between the sides of the casing and chamber walls, and without these roller-lock actions would be susceptible to ripping rims off casings and causing other extraction issues. Once-fired brass from a JP5 (or an HK MP5) has these telltale carbon streaks.

Upper and Lower Receiver Set, Fire Control Group And Peripherals

All JP5s are built around JPE’s billet-machined G940 receiver sets. These exquisitely machined receivers have no demonstrable play between the upper and lower halves. The upper receiver is slick, as the JP5 doesn’t need a forward-assist or brass deflector, but deflectors can be added later. Mounting optics on the JP5 is straightforward due to the upper’s standard Picatinny rail receiver top.

The JP5’s lower is fully ambidextrous and easy for both left- or right-handed shooters to shoot well. A core feature of the JP5’s lower receiver is a magazine well that is designed to accept and feed from any 9mm Glock-pattern double-stack magazine. Given the popularity of Glock pistols and their magazines, utility of this feature is self-explanatory. In addition to the fit and finish of the upper and lower halves, everything else about the receiver set is immaculate, including every detent and roll pin. Even the extra pieces machined onto the sides to accommodate the roller-lock action into this gun fit seamlessly. As a result, the build quality of the JP5 feels bespoke.

The JP5’s magazine catch is impressive, and reminds me of the classic Norgon unit, but on steroids and reversed. Its main part consists of a generously knurled finger-pad. I find myself using it despite the fact that I’m left-handed and I could just as easily push the standard AR-style button that caps the other end. The JP5’s mag catch doesn’t protrude, so worrying about a magazine inadvertently falling out when bumping into something isn’t a concern. In a similar fashion, the JP5 is equipped with ambidextrous bolt catches, not unlike what’s seen in today’s high-end ambidextrous AR-15 lower receivers.

My specimen is outfitted with JP’s “standard” single-stage AR-15 pattern trigger. Even covered in fouling and well-worn, 10 breaks averaged to 2 pounds, 12 ounces. The break is crisp and precise, and a trigger like this one wouldn’t be out of place in any precision AR rifle. The ambidextrous safety/selector assembly, like the trigger, is another JPE designed component and is of the same high quality. The charging handle included with this carbine is a Radian Raptor, a popular choice in aftermarket charging handles.

Barrels, Handguards, and Stocks

JPE builds its standard JP5s with a light-contour ultra-match barrel. It’s air-gauged, button-rifled and manufactured with a 1:10-inch twist rate, which is well-suited for 9mm ammunition. On this build, the muzzle has JPE’s Vertical Port Compensator, which is pinned and welded in place. Because it’s designed around the unique characteristics of the 9mm cartridge, it’s very efficient at negating any muzzle climb.

JPE’s proprietary full-size 12.5-inch Mk. III tubular handguard shrouds the barrel. Although the Mk. III has its own ecosystem of attachment and accessory mounts, the combination of its knurling and vent holes makes it easy to grip while also keeping much of the barrel’s surface area exposed to the ambient air for better cooling.

My unit shipped with a Hogue Overmolded carbine stock and pistol grip, but I switched these out with a Magpul MOE-SL and K2 pistol grip (personal preference) for this review. One of the JP5’s benefits after all, is its ability to accept common AR-15 pattern accessories.

Shooting The JP5

My interest in the JP5 has many facets, from the technical to the practical. But the chief interest is that of having a reliable 1:1 emulator of the 5.56 NATO carbines I typically shoot. With a few obvious differences, I find that the JP5 can closely deliver that experience.

So in the spirit of emulating my 5.56 NATO carbines, I mounted a Trijicon AccuPower LPVO on a Primary Arms 30mm mount, and I’ve shot nearly 800 rounds (and counting) with this configuration. Thus far, I’ve shot two USPSA matches (PCC division) and brought this carbine to Templar Defense’s Rifle-1 basic carbine course. Between the weight of the carbine and the LPVO along with its smooth operating action and compensator, recoil is non-existent which makes this carbine extremely easy to shoot. Shooting the JP5 in matches is one thing, but during Templar’s Rifle-1, I had no problem keeping up with the class and its curriculum thanks to the identical manual-of-arms the JP5 shares with AR-15s.

BCG and ammo JP5s are tuned from the factory to cycle the standard spectrum of 9mm ammunition, and the action can be tuned for specialty loads within reason. Naturally the lion’s share of what I’ve fired through this carbine has been FMJ/target 115-and 124-grain rounds. This review also includes defensive ammo from Hornady and Nosler: the 124-grain Critical Duty +P and the 115-grain ASP JHP, respectively. From a rest, this carbine was printing 2.5-inch real-world groups at 50 yards on average. There’s no doubt that one could find or tailor some handloads to shrink those groups, but despite its very nice trigger, this isn’t a precision carbine. At “pistol-distances” the JP5’s accuracy isn’t a concern in the least. For maximum accuracy across the entire JP5 family, JPE recommends handloads or premium factory ammunition loaded with high-end jacketed hollow point projectiles as that type of bullet tends to yield tighter groups. (The same is true for handguns).

Between the weight of the carbine and the LPVO along with its smooth operating action and compensator, felt recoil is non-existent which makes this carbine extremely easy to shoot. Adding to the easy factor is the fact that 9mm doesn’t have nearly the same concussion and muzzle blast that 5.56 NATO ammunition does.

After extended shooting sessions, the receiver area and magazines tend to become sooty and fouled, just like a direct gas impingement AR-15 with a traditional high-back pressure suppressor. But, this is just life with any blowback firearm. My unit seemed temperamental in locking back with certain magazines but not others. I’m not sure if that’s a magazine issue, or something specific to this gun, whose lifetime round count is unknown. From the looks of the carbon deposits in the compensator, perhaps this carbine has fired several thousand. Regardless, it has been extremely reliable in cycling and firing everything I’ve put to through it. I had no actual problems with feeding using Glock factory 33- and 17-round magazines or Magpul GL9s.

The Desire To Burn Up The Whole Stash

Aside from its neat MP5-derived action, shooting the JP5 is a lot of fun. In fact, it’s so fun that it makes you want to shoot up every last round of 9mm in your stash at home. There’s also something to be said for the fact that it closely emulates the more authentic “feel” of an AR-15, including the height-over-bore offset, a critical element in carbine training and something that citizens who use carbines defensively must always keep in mind. I think its emulation of a “real” AR-15 is its single biggest positive element. Look at it this way: compared to a 5.56 NATO round, it costs 50 percent less to pull the trigger. And yet, the shooter is still getting a full “repetition” of meaningful trigger. Since the JP5 has a more realistic weight and can be “kitted out” in the exact same way as any defensive 5.56 NATO carbine, training with it doesn’t feel like a compromise, the way training with .22 LR rimfires firearms might.

Unfortunately, the JP5’s largest con is its base price of approximately $3,240. These guns are not cheap, but the care and quality put into each carbine is self-evident.

Special thanks to GT Distributors for providing additional 33-round 9mm Glock factory magazines for this review.

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