JR_1 copyMany firearms companies purport to manufacture truly innovative products, but few actually do. While the American ideal of “building a better mousetrap” lives on, innovation too often gives way to status quo.

The safe bet is for a company to manufacture products for which there is already a clearly established market. Fortunately, companies such as Just Right (JR) Carbines aren’t interested in playing follow the leader. Instead, they are carving out their own niche in the industry. In JR Carbines’ case, it’s by offering pistol-caliber AR-15-style carbines.

JR_8 copy

The six-position stock is of the M4 style only draped in a water-transferred American-flag motif. Besides basic black, many colors and patterns are available with JR Carbines including Muddy Girl, ReaperZ, A-TACs Foliage/Green and others.

Pistol-caliber carbines are nothing new. In fact, they’ve been around since the 19th century. The obvious advantage of such firearms is that they are more easily wielded than longer rifles chambered in more traditional calibers and much lighter recoiling. Thanks to the longer barrel, longer sight radius, cheekweld and shoulder mount, carbines are far more accurate than a handgun chambered for the same cartridge. In addition, the increased velocity generated by the rifle’s longer barrel can extend the effective range of the round. Then there’s the convenience of being able to shoot the same ammunition from a rifle as from a pistol.

Just Like an AR … Only Different JR Carbines makes unique firearms in that they offer the user-friendly features and modularity of the AR-15 platform, yet they accept popular Glock, Smith & Wesson M&P or 1911 magazines, depending on how the carbine is configured. JR Carbines are currently offered in 9mm, .40 S&W and .45 ACP. Don’t know which to choose? Not to worry. You can easily swap calibers by purchasing a conversion kit.

Southpaws will appreciate that the JR Carbine’s bolt can be configured so that spent cases are ejected from the left side of the rifle, as opposed to in their face. The bolt handle can also be mounted on either side of the rifle.

Although the JR Carbine is patterned after the AR, there are a number of differences, including the bolt operation. To cycle the bolt, simply pull the bolt handle rearward and release. To lock the bolt to the rear, pull the bolt rearward and then downward, into the notched bolt catch. Of course, since it fires pistol-
caliber bullets, the JR Carbine’s magazine is significantly different than the typical 5.56/.223-style AR mag.

JR_6 copy

Unlike other AR-type rifles, JR Carbines offers its user a knurled bolt handle to charge and/or lock the action open. It can be oriented for either right- or left-side operation.

Due to the dramatically different magazine well, the JR Carbine’s mag release is not accessible to your trigger finger when you’re attaining a proper shooting grip. This is the rifle’s biggest drawback because it prevents you from reloading it anywhere nearly as efficiently as reloading a standard AR. Of course, you could limit the need for reloading by employing a high-capacity magazine, unless you’re in a state such as California where even “standard”-capacity magazines are prohibited by law.

The California-compliant model G&A evaluated was equipped with the dreaded but legally mandated bullet button, located on the left side of the rifle. As the name implies, a tool such as the tip of a bullet or the purpose-built metal plunger that came with the rifle must be used in order to remove the magazine. This feature prevents the mag from being considered “detachable,” which — when combined with other standard AR features such as a pistol grip, telescoping stock or flash hider — could classify a centerfire rifle as a so-called “assault weapon.”

Similarly, the 15-round 9mm Glock 19 magazine that shipped with my JR Carbine was blocked to only accept 10 rounds in accordance with California state law.

JR_4 copy

A metal plunger is supplied with the California-compliant models to switch magazines.

Unlike an AR, which comprises an upper and lower receiver that can be easily disassembled without tools, the JR Carbine’s magazine well and firing assembly are secured to the receiver by three takedown screws located on the right side of the rifle. This enables you to easily switch magazine wells, but the tradeoff is that disassembling the carbine for routine cleaning is more of a chore than with an AR-15-platform rifle. In fact, one has to remove the buttstock assembly to access the bolt. Although this procedure is simple enough, it might cause AR aficionados to groan.

Another significant difference with the JR Carbine is that it relies on a straight blowback operation (like a sub-machine gun) rather than direct-impingement (DI) or piston operation, as is typical of the AR. Straight blowback is a simple, reliable operation in which the spent casing is forced rearward by expanding gas created when fired. As the bolt moves rearward, the casing is extracted and ejected. Continued rearward movement cocks the hammer and compresses the buffer spring, which then sends the bolt forward, feeding and chambering another round. With traditional AR-15-platform rifles, the bolt is locked into place by locking lugs, and the cartridges are of relatively high pressure, rendering straight blowback operation impractical.

Despite its unique characteristics, the JR Carbine will seem like an old friend. It is compatible with standard AR furniture, so customization options are virtually limitless.

The model we tested donned an American-flag pattern and a midlength quad rail housing a 17-inch, button-rifled, 1:16-inch-twist barrel with a 1/2×28 threaded muzzle for the mounting of a muzzlebrake or suppressor. The Picatinny rail atop the receiver facilitates the mounting of optics such as the BSA red dot sight, which arrived with our sample.

JR_3 copy

Unlike the usual AR-type rifle, JR Carbine’s upper and lower receivers are secured to one another by three screws on the right side.

The rifle is a handy 6½ pounds. The M4-style telescoping stock can make the overall length between 30¼ and 33½ inches, based on shooter preference.

The JR Carbine’s A2 grip enables the shooter to easily manipulate the AR-15-style selector switch and access the standard semiautomatic AR trigger, which tested cleanly at about 6½ pounds.

The receiver, trigger housing and magazine well are machined from aerospace-grade 6061 T-6 aluminum in New York State. This was a New York SAFE Act-compliant model with a fixed, “Sporter”-style stock; a nonthreaded 17-inch barrel; and a reduced-capacity Glock-
compatible magazine.

Given its patriotic water transfer, this JR Carbine got quite a few stares when it was uncased at the range. Settled at the bench, we hoped the rifle would prove worthy of the American badassery the Stars and Stripes intrinsically exudes. We have to admit, we were impressed with the way the rifle performed.

Although a red dot or iron sights would be an appropriate paring with an AR-15-style pistol-caliber carbine, we replaced the supplied BSA sight for overkill at 50 yards. The accuracy-extracting scope was in the form of a Bushnell Elite Tactical DMR 3.5-21x50mm.

JR_10 copy

G&A tested JR Carbine’s 9mm Flag Gun, which feeds from Glock 19 mags. Bullet-nose profile was not an issue during testing.

The JR Carbine was rather quiet, and the recoil was surprisingly light. What really surprised us was how accurate it was (with the scope, of course). The 115-grain Federal Range Target Practice ammo produced a 1.20-inch best five-shot group and an average group size of 1.71 inches. That may not seem impressive by rifle standards, but try doing that with a pistol.

The midweight 124-grain Pierce Performance ammo didn’t fare quite as well. Groups widened considerably, with the best measuring 2.32 inches and the average a lackluster 4.45 inches.

The Winchester 147-grain PDX1 Defender was the star, with the best group of the day. It measured a respectable 1.15 inches. The average group size with this heavyweight cartridge measured 1.42 inches.

Admittedly, we assumed that the JR Carbine might be a little finicky, but it ran without so much as a hiccup. If it had malfunctioned, we probably would have written off the rifle as just a novelty. However, since it was reliable and produced more than fighting-effective accuracy, G&A is convinced that, in addition to being fun to shoot, the JR Carbine is a legitimate home defense option. It’s also a great platform to instill a sense of confidence in a new shooter, as evidenced by an impromptu experiment we conducted at the range.

We coaxed a somewhat-reluctant woman to give the JR Carbine a try. Not surprisingly, after a few shots she commented that there was very little recoil. She was all smiles when she realized how easily she could hit her target. For a moment, we thought we might have to wrestle the rifle from her, but she eventually gave it back — empty.

JR_11 copyThe JR Carbine is an innovative, practical firearm. While it’s certainly not a replacement for a handgun or a traditionally chambered AR, it is easier to shoot than a pistol and softer-recoiling than a rifle (not to mention less expensive to shoot).

Our conclusion: What could be cooler than an AR chambered in 9mm that runs on Glock mags? If you’re in the market for a pistol-caliber carbine, give the trendsetters at Just Right Carbines a look.

Load Comments ( )

Don’t forget to sign up!

Get the Top Stories from Guns & Ammo Delivered to Your Inbox Every Week