8" 300BLK Complete Low Profile Piston Upper with A.P. 7" M-Lok Handguard

A: We use our own uppers that are spec'd to our drawings as we use a rocker bushing in our 300BLK in order to rock the op rod out on pistol gas operating length uppers. You can see our 300BLK piston upper video in how the rocker bushing works here: https://www.blackriflearms.com/PISTON-VIDEOS_ep_40.html

We have not heard of any fitment issues with Aero lowers.

A: No, not at this time as we designed our proprietary barrel nut for use with Aero Enhanced Handguard with our piston uppers.

A: No, this product is a complete upper with no lower parts included. This complete upper is ready to pin onto a complete lower. Buffer or any lower parts are considered lower parts and not part of this complete upper.

A: Our 300 Blackout system is nonadjustable. It was determined during our R&D process that by utilizing a piston of a particular size and proper positioning of the gas port location we could achieve outstanding reliability without adding the complexity of a regulated system. Although we are known for our regulated piston systems and really believe in them only because they offer significant benefits with typical rifle calibers especially with suppressed firearm due to suppressor backpressure that may increase bolt carrier velocity by as much as 30 percent. Our regulators provide a means to mitigate over gas situation and compensate for underpowered ammunition as well. All of which is common with standard rifle calibers. However, 300BLK self-mitigates these gassing issues to a significate degree by virtue of its design. For example, with subsonic ammunition you have a bullet that is typically twice the weight of a supersonic bullet, and it is moving at less than haft the velocity. This creates a situation where subsonic bullets are in the barrel about twice as long providing a longer gas impulse. Conversely supersonic bullets are moving about twice as fast and at much higher pressure. These characteristics enable us to utilize our piston system and gas port positioning to effectively balance between the longer dwell time of subs versus higher peek pressure of supersonic ammunition. The key here is we balancing gas pressure and dwell time with piston size and gas port positioning to optimize reliability, thus eliminating the need to regulate our 300BLK system.

A: Yes our bolt carriers are full auto. Our uppers are mil-spec so any drop in auto sear designed to be used in mil-spec uppers will work. We run our systems full auto all the time.

A: Yes it comes with a bolt carrier. It's a complete upper receiver ready to be pinned onto a lower.

A: We estimate in about 3 to 4 weeks, but it could be a little longer.

A: Due to the length of the 8" barrel, it may not lock the bolt back on the last round. The 8" 300BLK will shoot subsonic optimally with a silencer and supersonic with or without a silencer. If you want to shoot subs with or without a silencer please look at the 10" 300BLK piston uppers.

A: Sorry, we do not sell these separately. They are designed to be utilized with our uppers and conversions.

A: Barrels are in production now, so we are hoping in about 4 to 6 weeks.