Enlarged ejection port to freely pass 458 SOCOM all the way up to 50 Beowulf .
The STT Big Bore PILLAR upper receiver is incredibly light!
With so many AR-15 upper receivers on the market today we decided to challenge ourselves and create something better, something different. Being better was not enough -- we needed to design an upper that overcame the shortcomings we saw in the current offerings . It needed to be lighter, stronger, and different, and all while looking good doing it. We weren’t going to settle for just hacking another receiver out of a block and calling it good.
The first thing people will notice is the truss pockets. With the shooting styles of today’s shooters everyone wants to run 15” & 16” long rails and grip the rail as far out as possible to gain the most control of the rifle. That’s like attaching a 16” lever to the rifle. The truss design acts similar to a bridge that carries and distributes the stress across the entire platform verses putting all of the stress on the material right behind the threads of the receiver. The extra strength gained from this design is not only to help the receiver. It also in turn helps improve your accuracy.
When most people think of a billet receiver they think of a blocky, heavy, thick design that is CNC machined. We wanted to break that mold too. Thru the use of 3D CAD modeling software we were able to save weight in places that extra material didn’t have a purpose, such as the forward assist block and the shell deflector. Normally on billet uppers those are left bulky due to the difficulty of removing material on all of those angles. After all of was said and done the new STT receiver came in at only 8.2 ounces. That’s lighter than some slick side uppers!
Overall we strived to offer the shooter something that wasn’t just another pretty face in the crowd. We wanted an upper that would really address the issues and shortfalls of todays shooter.