Gear Review: IGB barrel for Glock to rifle carbine conversion kit

The IGB barrel on the CAA Micro Roni. (Photo: Eve Flanigan)

Recently, I reviewed the CAA Micro Roni Glock 17 non-NFA carbine kit. Integral to the setup is the Austrian-made Impulse Gun Barrel, more commonly called the IGB. In this case, the IGB is a 16-inch threaded model.  This review shares some highlights about the barrel and its performance.

Construction

IGB barrels are made with modern processes. Constructed from cold forged steel, IGB’s machining process produces a mirror finish on the interior. Hardening is done by Plasmanitration, which produces diamond-hard surfaces without flaws common to older methods. Plasmanitration creates a dark gray, corrosion-resistant finish. Inside, tooling of the groove-to-field angle, with slightly rounded edges, is said to enhance durability and ease of cleaning.

The company claims to produce solid tolerances and a proper fit. This test was malfunction-free, save for one brand of JHP which uses a silver, nickel alloy case. The same G17 that unfailingly ran this ammo without the Micro Roni and IGB after the test “refused” to do anything but light strikes on the primer while fitted with these add-ons. A variety of other ammunition presented no problems. This is not to single out the barrel for this problem, as it was impossible, legally speaking, to eliminate it from the equation. It’s simply a repeat of the familiar lesson to test any ammunition one might use for self-protection in the system for which it’s intended.

Using the IGB barrel

Installation is simple—insert the barrel as a replacement for the stock one. No adjustments necessary.

Firing the Micro Roni fitted with the IGB, the already-soft recoil of a Glock 17 is flattened even more. With a proper shoulder mount, it’s easy to stay on target for follow-up shots. 

Accuracy is much improved over a regular Glock. Firing on a 36-inch square target at 185 yards, my normal hit rate with a naked G17 is 40-50 percent. With the IGB barrel and Micro Roni, the hit rate increased to 60-70 percent, with a mix of brass-and aluminum-cased FMJ.

The barrel touts an impressive 4 MOA group from 25 yds away. (Photo: Eve Flanigan)

At closer distances, accuracy improvements are even more dramatic. At 25 yards, an impressive 4 MOA group was achieved with Federal 147 grain jacketed hollow point. Group size increased as grain weight decreased. This could be a reflection of our small sample size of three ammo brands/weights, or perhaps the heavier bullet provides more stability to the barrel, which has substantial play at the muzzle end. Regardless, accuracy with the barrel in place is far superior to any possible with just the pistol.

Especially since the test would include firing on steel, I inquired with my industry rep at YRS, Inc. about muzzle velocity—is it more like a rifle or a pistol? The answer is somewhere in between. On average, a round picks up 14 percent velocity with a 10-inch barrel. Barrels longer than that don’t offer additional gains. Of course, that estimate is dependent on the load. For safety, I stayed at least 20 yards from the hangers provided by CTS Targets. That’s far more than at USPSA matches, but I’ve also experienced splash-back at those competitions.

The other asset

In addition to impressive accuracy gains, the IGB allows consumers to avoid the costly, time-consuming NFA permitting process while still having what amounts to a short-barreled rifle, for a total cost comparable to the least expensive of entry-level AR15s or most of the pistol-caliber carbines on the market. It extends the range and versatility of a Glock, and properly accessorized, makes a great stand-in for the many applications of a “real” carbine.

The IGB barrel from YRS retails for $350. (Photo: Eve Flanigan)

Impulse Gun Barrels are guaranteed to the original purchaser to be defect-free, except for abusive use. Currently, YRS has them available for $350. YRS is actively seeking new US distributors, and invites contact from any potential dealers or distributors reading this article. It’s easy to imagine that prices could even decrease if and when IGBs gain a wide presence on the market.