2A Armament’s Builder Series was designed to provide your next build with rugged, lightweight, reliable, and best of all affordable components. The Builder Series complete upper receivers are no different. These flat-top, optics ready receivers feature the Builders Series free float M-LOK handguards machined from genuine USA certified 6061 aluminum extrusions with full length top-rails and three tracks of M-LOK slots to provide plenty of space for your favorite accessories. The upper receiver is from the Palouse-Lite series that are forged from 7075-T6 aluminum with a lightweight slick side design without forward assist. Even better, these uppers are ready to roll from the factory, simply add your favorite sights, drop it on a complete lower and hit the range!
- 16” barrel chambered in 5.56 NATO
- 4150 CMV barrel made by ballistic advantage
- 1:7 twist rate and 1/2×28 threads
- Low profile .625” steel gas block
- T3 compensator
- M16 bolt carrier group Nitride finished
- 9310 bolt MPI
- Palouse-Lite 7075-T6 forge aluminum receiver
- Free float M-LOK handguard
- BCM-Mod4b ambidextrous charging handle
- Weight: 3 lb. 15 oz.
The 16” 5.56 barrel is made by Ballistic Advantage out of 4150 CrMoV steel with a 1:7 twist rate optimized for 62 grain ammunition. Attached to the 1/2×28 threads is the T3 compensator to reduce felt recoil. The bolt carrier group is high quality as well with the carrier being made from 8620 steel and the bolt being made from 9310 steel and then Nitride finished. Additionally, it is magnetic particle inspected to ensure quality machining. This complete upper receiver group also features a BCM-Mod4b ambidextrous charging handle.
2A Armament is not just another firearms manufacturer. They are committed to exceptional craftsmanship and quality in the products they make. State of the art manufacturing paired with hand finishing of every part result in firearms with unmatched fit and finish.