RDI RAK556 5.56 POLY KRINK W/TRUNNION

The RDI RAK556 5.56 Poly Krink is a semi-automatic pistol built on a milled receiver and designed for shooters who want a compact, controllable platform chambered in 5.56x45mm. This 21-inch overall length pistol splits the difference between maneuverability and velocity—the 8.5-inch 4150 Nitride barrel delivers rifle-caliber performance in a form factor that doesn't demand the tax stamp or SBR paperwork of a traditional short-barrel rifle. The RAK556 uses a modular rear trunnion compatible with a pig-nose brace adapter (where legal in your jurisdiction), giving you flexibility in how you configure it for your shooting setup.

Built tough from the ground up, the RAK556 features a fully heat-treated mil-spec stamped receiver paired with forged components—trunnion, bolt, and carrier—that handle sustained fire without compromise. The chrome-lined piston and carrier keep maintenance reasonable, and the 4-piece muzzle brake with chrome-lined funnel helps manage recoil and flash. A hinged dust cover keeps debris out when you're not shooting, while the spring-loaded firing pin adds reliability under field conditions. The lower hand guard incorporates a stainless steel heat shield to protect your grip hand, and the serrated upper hand guard ensures you maintain purchase even when things get wet or dirty.

Controls are shooter-friendly: an extended magazine release makes reloads faster, and the bolt hold-open safety lever gives you tactile feedback at the critical moment. The machined side-mounted scope rail lets you run an optic if your application demands it. This is a serious pistol for serious shooters—whether you're running it at the range, in a home-defense role, or as a truck gun. Feeds standard 5.56 magazines, takes 30-round capacity, and handles the full spectrum of .223/5.56 ammunition you're likely to have on hand.

Key Features

• 21-inch overall length—compact enough to handle, long enough to deliver velocity
• 4150 Nitride barrel (8.5 in) for corrosion resistance and longevity
• Fully heat-treated mil-spec receiver and forged internal components
• Modular rear trunnion accepts pig-nose brace adapter where legal
• Chrome-lined piston and carrier for reduced maintenance
• Serrated upper hand guard and lower hand guard with stainless steel heat shield
• Extended magazine release for faster reloads
• Bolt hold-open safety lever and hinged dust cover
• Machined scope rail for optic mounting
• 4-piece muzzle brake with chrome-lined funnel
• Black oxide finish throughout

Specifications

Frequently Asked Questions

Can I attach a brace to this pistol?

The RDI RAK556 features a modular rear trunnion designed to work with a pig-nose adapter using 10-32 screws. Brace legality depends on federal ATF guidance and your state/local laws—check current regulations before configuring your rifle.

What magazines does this pistol take?

The RAK556 feeds standard 5.56mm magazines and has a 30-round capacity. You can use any mil-spec 5.56 magazine your range or jurisdiction permits.

Is this suitable for optics?

Yes. The RAK556 includes a machined scope rail mounted to the side of the receiver, allowing you to mount an optic for aimed fire.

What's included with this pistol?

The description provided covers the pistol and its integral features. For a complete list of what ships in the box—spare parts, manual, tools, or accessories—contact Bosque Outdoors directly.