October 02, 2024
By D. Faubion
Editor's Note: This article was origanlly published in Firearms News' sister publication Suppressor magazine. Pick up a copy of Suppressor at your local magazine stand, Walmart, Barnes & Noble, or major book retailer. You can also find a copy online at OSGNewsstand.com .
The Griffing Armament GP 7 is a direct-thread .30-caliber suppressor with an MSRP right at $650. Without the National Firearms Act (NFA) of 1934, permanently attaching a muzzle device to a barrel wouldn’t happen. Functionally, there’s no reason to pin and weld or silver solder a flash hider, muzzlebrake, or suppressor to your barrel. It only causes complications. But we don’t live in a rational world. The NFA is filled with legal hurdles. For rifles, the barrel must exceed 16 inches. This is a handy length — until you add a 7-inch suppressor. It then gets loooooong. There are alternatives. One is to pay $200 to the BATF for a short-barreled rifle (SBR). This accomplishes the goal, but you now have a two-stamp gun ($200 each for suppressor and SBR) that requires .gov permission to leave your home state. Not ideal. Another option involves chopping your barrel at a manageable length, say 12.5 inches, threading it, and permanently attaching a suppressor. If total length exceeds 16 inches, you’re clear. Ballistically, you lose some juice, but you now have an SBR-length rifle that can travel freely and doesn’t require the second $200 tax. That’s exactly what you see here. Using a GP7 from Griffin Armament, we gave this custom Remington Mohawk 600 in .308 a perm. The 18.5-inch barrel lost 6 inches and was threaded. Once the the GP7 was timed, it was pinned and welded. This lil’ 600 is now short, handy, quiet, and — most importantly — legal.
This .308’s barrel went from 18.5 to 12.5 inches to make room for Griffin’s GP7 suppressor.
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GRIFFIN GP7 But not every can is built for this purpose. Luckily, we have Griffin Armament. Their GP5 (5.56) and GP7 (.308) suppressors are one-piece designs that enable permanent installation. Made of 17-4 stainless steel, the GP7 weighs 13.2 ounces, measures 7.25 inches in length, and is rated up to .300 Rem. Ultra Mag. In addition, both cans come predrilled with a .125-inch hole for the tiny pin Griffin Armament includes along with shims. Pinning and welding isn’t complex, but unless you’re a machinist or gunsmith, it’s not a DIY job. Once the barrel is cut and threaded, use the shims to time the GP7 at the 6 o’clock position. This isn’t critical for function; it’s only to keep the weld out of sight. Next, align a drill press with the suppressor’s pin hole. Shallow drill the muzzle threads until the tiny pin sits inside the hole. Avoid drilling too deep. Finally, add a spot weld to make the pin a permanent part of the suppressor. You’re done. Rest assured, much like a tattoo or marriage, “permanent” doesn’t mean forever. If the barrel is shot out or damaged beyond repair, grind out the spot weld, remove the pin, and unscrew the GP7 suppressor. It’s that easy.
With the GP 7 suppressor permanently attached, the rifle no longer needs an additional tax stamp.
