You have no items in your shopping cart.
Search
Filters

The 300 AAC Blackout, commonly called just 300 Blackout, uses the same magazines, and bolt carrier groups as the .223 / 5.56. The only difference is in the barrel and muzzle device, but gives you a much higer energy round while still using your AR-15  lower receiver.

Our rifle uppers use both US Made and imported hand guards but all other parts are guaranteed US Made.

Our pistol uppers use both US Made and imported hand guards, but all other parts are guaranteed US Made.

Most importantly we use only US Made Steel Gas Blocks on any model using a low profile "micro" gas block

Texas Gun Builders' upper assemblies are available in Flat Dark Earth, Burnt Bronze, and many other Cerakote and KG GunKote Colors, and are made from the highest quality materials and with the exception of using imported hand guards on some models... every other part is Made in the USA!

These uppers are not just assembled in Texas, several of the parts are made right here in Texas and Texas Gun Builders runs our own Cerakote and KG GunKote application facility.

So with the high-quality materials, meticulous workmanship & incredible pricing you can't go wrong.

We use Anderson Manufacturing flat top Mil-Spec upper receivers with M4 feed ramps, forged and then CNC Machined from 7075-T6 Aluminum, providing you with the hardest and most durable material of any upper receiver!

The barrels are made from 4150 Gun Quality Parkerized Chrome-Moly Steel, Heat or 416R stainless steel and Treated to RC 28-32 Hardness, and Stress Relieved! The barrels are incredibly accurate and durable.

The gun builders at Texas Gun Builders have over 40 years combined experience, led by an ex-Army Armorer. Our uppers are torqued to military specs & quality checked continuously.

These upper assemblies are available with or without the BCG and Charging Handle and ready to drop it onto your AR-15 Lower... or have us supply the lower.

You can find lowers here.

View as
Sort by
Display per page

AR-15 Upper Assembly - 16in SS / 300 Blackout / 1:8 / 12in TGB M-LOK AR-15 Handguard / Rail with M-LOK Rail Attachment

300 AAC Blackout AR-15 Upper Assembly in Black Anodized with a 16 inch Stainless Steel barrel. INCLUDES BCG and Charging Handle
$387.00 $407.00

AR-15 Upper Assembly - 16in SS / 300 Blackout / 1:8 / 12in TGB M-LOK AR-15 Handguard / Rail with M-LOK Rail Attachment / NO BCG

300 AAC Blackout AR-15 Upper Assembly in Black Anodized with a 16 inch Stainless Steel barrel. NO BCG or Charging Handle
$277.00 $297.00

AR-15 Upper Assembly - 16in SS / 300 Blackout / 1:8 / 12in US Made Airlite Key Mod AR-15 Handguard

3.7lb 300 AAC Blackout AR-15 Upper Assembly in Black Anodized with a 16 inch Stainless Steel barrel. INCLUDES Low Mass BCG and Charging Handle All US Made Components
$429.00 $449.00

AR-15 Upper Assembly - 16in SS / 300 Blackout / 1:8 / 12in US Made Airlite Key Mod AR-15 Handguard / NO BCG

300 AAC Blackout AR-15 Upper Assembly in Black Anodized with a 16 inch Stainless Steel barrel. All US Made Components. BCG and Charging Handle ARE NOT INCLUDED
$314.00 $339.00
View as
Sort by
Display per page