Frog Arms, LLC

  This is truly a one-of-a-kind build. Featuring the Bear Creak Arsenal’s patented right-side charging upper, Adams Arms carbine piston kit, and Frog Arms custom lower. This build required carbide bits to drill and tap the holes in the side of the Adams Arms bolt carrier using a template based on the Bear Creek direct-impingement bolt carrier. This transformed the Adams Arms bolt carrier into a right-side charging bolt carrier for this custom upper. Adams Arms piston is installed with their 15-inch M-Lok rail and barrel nut (the Adams Arms piston does not work with the Bear Creek barrel nut). In defense of Adams Arms, their piston kits were originally designed for mil-spec barrel nuts. Adams Arms are great pistons and I have a couple in my personal collection. Compatibility with more manufacturers’ barrel nuts is one of the reasons Frog Arms is now using Superlative Arms piston Kits.

Standard build with Del-Ton upper. The latest builds are with Bear Creak Arsenal uppers: California-compliant variant with fixed non-thumb through stock, fixed ten-round magazine, and no muzzle device: Bear Creek Arsenal .224 Valkyrie upper variant for long-range target or varmint hunting: All of these rifles feature Frog Arms trigger jobs. Zero pre-travel/take-up and crisp break 3-3.5 Lbs. stainless steel mil-spec triggers polished to perfection:

Latest custom builds from Frog Arms using Superlative Arms piston kits. These pistons have adjustable gas blocks and their patented “bleed off” mode that allows proper cycling of the bolt carrier group. These pistons can also be used in restrictive mode, so the shooter can adjust manually to fit conditions. Below are the carbine and pistol length systems. For more details see their website https://suparms.com/