Micro ARP 300 Blackout Pistols & Uppers

300 Blackout Micro ARP Pistols, Uppers & Kits

Micro ARP 300 Blackout builds are designed to deliver exceptional performance from compact AR platforms. The 300 BLK cartridge was specifically developed for short barrels, making it one of the most popular choices for Micro ARP pistols, uppers, and custom builds.

Whether you're building a compact range firearm, home-defense platform, or suppressor-ready setup, 300 Blackout provides excellent energy, versatility, and reliability in short-barrel configurations.

Browse our selection of Micro ARP 300 BLK pistols, uppers, barrels, and components engineered for compact performance.

FAQ

Why 300 Blackout in a Micro ARP?

300 BLK burns efficiently in very short barrels and works well with suppressors, so it keeps more energy than 5.56 from a 4.5" to 5" barrel.

What magazines do 300 BLK Micro ARPs use?

Standard AR-15 magazines. Never mix 300 BLK and 5.56 ammunition: firing 300 BLK in a 5.56 gun is dangerous.

Do complete Micro ARP pistols ship to an FFL?

Yes. Complete pistols are firearms and ship to your local FFL dealer. Uppers and kits without a lower receiver ship directly where state law allows.

What does "SBR ready" mean?

The rear setup accepts a stock, but adding a shoulder stock to a pistol with a short barrel changes its federal classification. Do it only in compliance with NFA and state rules.

Related: all Micro ARP pistols and uppers · 5.56 Micro ARP · 300 BLK Micro ARP · 9mm Micro ARP