We hit the range with our Frontier Tactical 300 BLK build. Frontier Tactical is known for their versatile multi-caliber system called the WARLOCK (www.FrontierTactical.com; $1,200). When installed on an upper receiver one can twist the barrel out with a quarter turn and change calibers without the need for multiple upper receivers or optics. We ran a 16-inch Black Hole Weaponry barrel for the test. Sitting atop on the top rail was a Meopta ZD 6-24x56mm tactical scope (www.meoptasportsoptics.com; $2,070) set in a Warne LRSKEL30TG one-piece mount (www.warnescopemounts.com; $140).

Our Frontier tactical build (utilizing the Warlock multi-caliber retrofit) cycled every load that we tested. We found a good shooter at right around 800 FPS. Pictured is the Caldwell Rock that we use for all group testing to ensure steady shot placement for the best accuracy possible.

First up was the 110 V-MAX. Our main goal here was to see if such a light bullet could give us reliable function, even with the lighter charges. The powder did not disappoint and each and every load cycled flawlessly. Every round fired, ejected and even locked the bolt open on the last shot. We found good results across the spectrum, but found our barrel really sang with a charge weight of 22.2 grains, giving us a 5-shot group of measuring 1.516” at 100 yards.

While excited with the results, it was the subsonic loads that we were most interested in. Subsonic reloading can be a nightmare. Balancing a powder type, charge weight and bullet that will stabilize is tough enough, but to keep it under the speed of sound is the real challenge. Once you do obtain that perfect balance, there is still no guarantee that it will reliably cycle your action.

Coming to a crashing halt after tumbling, our subsonic round devastated the Clear Ballistics 10% FBI test gelatin. Our round stopped after 14-inches of arched penetration. While we did not drive the ELD-X bullet to its expansion velocity, it certainly deformed enough to transfer its energy into soft tissue.

Running the above loads in the same setup, we measured velocity on a Shooting Crony Gamma Master chronograph (www.shootingchrony.com; $220.95). We also deployed a sound meter app to see what the dB level would be out of a carbine length rifle. Results were outstanding! We were able to push our bullet as slow as 628.9 FPS and still cycle the action reliably. We worked our round up a bit and found that a powder charge of 11.3 grains gave us a subsonic round that flew in the 840 f.p.s. range and gave us a 5-shot group of 1.293” at 100 yards. Noise wise, it came in at just 79dB. How quiet is that? Let’s put it this way, the bolt closing registers at 67dB.

The Lyman Borecam Digital Borescope is a terrific piece of equipment for any gun owner to have. With the Borescope inserted into the muzzle of our Frontier Tactical upper, it’s shaft has measurements etched on it to easily get back to the same place for re-inspection.

Certainly happy with the results, that left just one more claim to test: the copper erasing properties. In the past I would test this claim by using a copper removing cleaner such as Hoppe’s foaming bore cleaner and noting if it turned blue or not. For this article we stepped it up a bit and got to use Lyman’s affordable new digital bore cam (www.lymanproducts.com; $299.95) and snapped some before and after pictures of a copper fouled patch about 8” down our muzzle that was there from previous firings. As pictured the copper that was left behind is no more . . . we actually shot the barrel clean!

Using the Borescope before testing the CFE 300 BLK, we found a very notable patch of copper fouling at 8” on the nose from previous use with factory ammo. Right: that same patch of barrel after our testing with CFE 300 BLK. The copper is no more.

Cheers to Hodgdon for doing it yet again and giving us a powder that is not only safe for the loads that 300 BLK shooters demand, but keeping it clean and accurate as well. Visit Hodgdon Reloading Data Center (www.hodgdon.com) for load data and more information, and Hornady’s website (www.hornady.com) for more information on bullet selection.