Finally, there's an easy way for you to get up and running when it comes to the world of the .300 AAC Blackout AR-15. We put together this build kit just for you, the person who's interested in getting to know the .300BLK cartridge.
This build kit gets you a 16" stainless steel barrel with a 1:8 twist rate to accommodate the most popular few grains of .300BLK rounds. You also get that ever-popular 13.5" free floating M-Lok handguard. You supply the mags and ammo (regular .223 / 5.56mm mags work perfectly with the .300BLK cartridge, in case you wanted to know), and either sights or optics of your choice, and you're good to go.
AR 15 RIFLE KIT SPECS:
Gas System: Carbine-length
Barrel Profile: M4
Barrel Steel: 416R
Barrel Finish: Stainless steel
Chrome Lining: No
Muzzle Thread: 5/8x24
Twist Rate: 1:8
Barrel Extension: M4
Gas Block Size: .750″
Gas Block Type: Low-profile
Muzzle Device: A2 Flash hider
Receiver Material: Forged 7075 T6
Receiver Type: M4
Handguard Type: 13.5″ lightweight M-Lok free float
Bolt Carrier Group Included: Yes
Bolt Steel: 9310 steel, magnetic particle inspected
Bolt Carrier Profile: Full-auto
Charging Handle Included: Yes
Overall Length: 24.5″
Benefits of the 16” Carbine-Length SS AR 15 Rifle Kit:
- 100% legal to own and ship to your front door
- Not considered a firearm – no FFL paperwork needed!
- 416R stainless barrel and Freedom parts kit ensure sub-MOA accuracy
- Prebuilt upper with gas system removes the guesswork of rifle making
- Includes bolt carrier group, free-floated M-Lok handguard and lower parts kit
AR 15 Rifle Kit Details (Expanded):
Barrel: 16″ carbine-length stainless steel, chambered in .300 AAC blackout, 1:8 twist rate, .750″ low-profile gas block, 13.5″ free-float M-Lok handguard, with an A2 “birdcage” flash hider.
Upper Receiver Assembly: Forged from 7075 T6 aluminum, hard-coat anodized in black for durability, features M4 feed ramps, and are made in the USA.
Bolt Carrier Group: The bolt carrier is made from 9310 steel and has a staked gas key and black nitride finish. The bolt itself comes complete with an extractor spring and O-ring insert. It accepts .223 Wylde, 5.56mm NATO, and .300BLK calibers (though you should NEVER attempt to use a caliber for which your rifle is not chambered), and is magnetic particle inspected.
80% Lower Receiver: Choose to receive a forged or billet Fire/Safe 80% lower receiver. Our lower receivers are anodized to match the upper receiver perfectly, and they come ready for machining of the trigger pocket and drilling of the safety selector and trigger pin holes.
AR-15 Lower Parts Kit: includes all parts needed to complete the lower receiver including pistol grip, mil-spec safety selector, and trigger/fire control group.
Lower Assembly: comes with complete buffer tube assembly including buffer, buffer spring, six-position buffer tube, latch plate, castle nut, and butt stock based on original Colt design.
Charging Handle: standard size, made from 6061 aluminum.
Please note: This build kit requires that the builder complete the 80% lower receiver themselves, but that’s the rewarding part of the experience (and the only way to build your own AR-15 without the need of an FFL transfer or serialization).
AR-15Lowerreceivers.com only ships within the United States. Federal legislation dictates we cannot ship our products internationally. Shipping of various parts and/or accessories are prohibited to states and locales (ie New Jersey, California, New York, etc…) with restrictions against certain parts and/or accessories (i.e. states with high-capacity magazine restrictions, manufacturing of semi-automatic weapons, etc..). It is your responsibility to be aware of your local firearms laws before purchasing from our website. We try our best to keep our shipping page current, but laws change daily.