M4 flat top with
-16" 1x16 twist chrome moly barrel (M4 cut on 16")
- M4 handguards
- flat top gas block or front site post
- birdcage flash hider
- Spike's Tactical .22lr bolt
- charging handle.
**FYI: The legal 16" barrel goes inside the receiver approximately 1.5" so the barrel looks like a true military 14.5" length. The barrel also comes with the end threaded 1/2 x 28.
This upper utilizes the correct 1:16 twist rate for the .22lr bullet and eliminates the problem of fouling AR15 gas tubes with dirty rimfire ammunition. All of our uppers come standard with Match Quality Green Mountain barrels.
Regarding the Spike's Tactical .22lr bolt. Our bolt is based on the Atchison design with improvements including the following: an electroless nickel finish gives it a much slicker, smoother finish so you do not have to run it as wet which means the bolt stays cleaner longer. We have changed some tolerances, beefed up the firing pin and pre-drilled for a ball-detent.
We test fire and tune all of the dedicated uppers in house with Federal bulk red-pack but some of the dedicated uppers may require tuning for your setup or ammo, un-notched hammers also work best with them. Most all full-auto's will require tuning and hot ammo. We recommend running a suppressor on a barrel length shorter than 10".
**Uppers do NOT come with a Magazine** Allow up to two weeks for delivery