J-M B Web / Glock / R. Taylor / Flatliner Compensator

The "Flatliner" compensator
makes two guns out of one.


by Robin Taylor

Flatliner compensator

Surfing through a gun show recently I ran across David Lanier of Accu-Match International. On display were barrel-mounted compensators for the Glock 17, 21, 22, and 23. Always a sucker for a new gizmo, I felt I had to have one. The ticket price read $218, so out flapped the checkbook. The Accu-Match "Flatliner" works like the conventional-style compensators mounted on the 1911's and TZ-75's of our day. The comp (a smallish 1 1/2-chambered one) threads onto a stainless steel replacement barrel, locking into place with a set screw. For the non-IPSC literate, "comps" trap escaping gases in a steel box attached to the end of the barrel. Those gases slam into baffles inside the box, pulling the gun forward, while ports in the top of the box vent gas upward to fight muzzle climb. The Flatliner has one large baffle, and two ports in the top. It's not a very efficient design compared to the latest four- and five-port versions, but it works without a lot of hand-fitting.

NO GUNSMITHING This is literally a drop-in unit. The new barrel and comp took only a few minutes to install using the stock guide rod and spring of my Glock 22. While another shooter looked on, I dissassembled the gun at a match, replaced the stock barrel, and was ready to go again in less than 5 minutes.

SOME PROBLEMS FOUND : Shooting the new barrel/comp revealed a few "problems." First, the chamber in the Flatliner barrel is a lot tighter than the notoriously loose Glock chamber. My slightly fat ammo worked perfectly in the stock Glock barrel, but seized in the Flatliner barrel. A 9mm version tried later on would only cycle using full-power 9mm loads -- a frustrating discovery. The tight chamber bit again once the ammo was re-sized, driving the pressures up and velocities over 1100 feet per second with a 175-grain bullet. Over the next several weeks I tested the .40-caliber Flatliner with a wide range of factory ammunition and handloads. The list included Eldorado Starfires, Fiocchi 145-grain hollow points, Remington/UMC 170-grain total metal jackets, handloaded 170-grain Remington hollow points, Ranier Ballistics 155 grain truncated cones, Speer Gold Dots, Tom Boy's 175-grain cast lead, and a slurry of ammo found rolling around in my range bag. I experienced 3 failures with the Starfires before I had the barrel throated, and I attribute those to bullet shape and overall length relative to a steep feed ramp. I also experienced several failures with the Remington/UMC after throating, but no failures at all with Fiocchi's fine 145-grainer in about 150 rounds. My reloads did well once I brought the cases inside SAAMI specs, scoring zero malfunctions in another 150 rounds.

HOW WELL DOES IT WORK ? Measuring change in muzzle flip is difficult in a Glock, but both Bruce Bennett and I noticed a dramatic decrease in recovery time. "It never left the target," Bennett said after hammering away on a steel IPSC silhouette. I had the same experience, watching my arms stay level instead of bouncing up slightly with the stock barrel. "Man, this beats the heck out of buying a Glock 24," Bennett smiled. Bennett and I were surprised to see the Flatliner shoot to nearly the same point of aim as my stock barrel. A good pair of click-adjustable sights such as the MMC would allow a shooter to swap barrels with abandon. Further testing found the Flatliner printing about 6 inches high at 25 yards, depending on the load tried. The Flatliner does not work with the Hart's Recoil Reducer guide rod. Bennet slapped his into my gun, but failures to cycle were the norm with most loads. Spent cases would eject, but the slide would not fully return to battery. Going back to the stock spring and guide rod immediately brought the gun back in line.

VELOCITIES INCREASE : As you might expect, the extra 3/4 inch of barrel used to attach the compensator kicks the velocies up slightly. Blazer TMJ's, which provide a religious 182 power factor in Bennet's gun, shoot 187 in his Flatliner. Lighter bullet weights, notably the 155 Precision Bullet load Bennet used saw their power factor ratings rise by as much as 10 (approx 60 feet per second). At the price, the Flatliner is inexpensive, and offers switch-barrel capability not found with the Aero-Tek Hybrid conversion. The Aero-Tek Hybrid is as effective, in our opinion, but it permanently modifies the gun. With that in mind, the Flatliner comes as a pleasant, and financially conservative surprise.

VERSATILITY THE MAIN SELLER : What makes the Flatliner competitive is its swap-barrel capability. Most compensating systems require permanent modifications to the gun (i.e. Aero-Tek, Mag-na-port, etc), and many are quite expensive. For someone who shoots IPSC on a budget, or would like to shave some time off their bowling pin scores without destroying their carry gun, the Flatliner may be for them.

COMPETITIVE TESTS : Mental errors destroyed my first "open" IPSC match, but I took the Flatliner to a bowling pin match a few days later. I shot my best time in recent memory (a 3.55 second run) and managed to place fourth out of a 30-man field. I shoot limited B, so for me, that was a heck of a good night. The increased weight, and faster recovery time of the Flatliner were very helpful.

WHERE DO I GET ONE ? Manufactured in Mesa, AZ, the Flatliner is distributed by David Lanier on the west coast. Lanier can be reached at (208) 743-3919 most days, or write to David Lanier, Lanier Sports, 1327 11th St., Lewiston, ID 83501. In Washington, contact Taylor Freelance, 4508 109th Ave. SE Snohomish, WA 98290 (360) 568-5370. In the Southwest, call the factory direct and ask for Lee Helm, or write to Accu-Match International, 1550 East University Drive, Suite F-1, Mesa, AZ, 85203. Phone: 602-834-0983, Fax: 602-834-1204, 602-834-7763.