About real PWS Diablo:
The Diablo Upper is Primary Weapons Systemsï¾’ answer to the 7ï¾” AR-15/M-16 series upper. Rather than simply bolting on an existing product and calling it revolutionary, PWS stepped back and designed a system from the ground up to work specifically with the extreme pressures of the 7ï¾” barrels.

We started with the barrel and after careful research decided on a 7ï¾” (not 7.5ï¾”) stainless steel polygonal bore barrel with a 1:8 twist. A match bolt carrier assembly is housed inside of a MUR-1 (mil-spec) upper receiver with a billet machined charging handle. Low profile quad rails give the most possible room for accessories and XTM rail covers.

The Diablo upper utilizes a long stroke piston system for additional dwell time and smooth recoil. The system is rounded out with the new CQB comp from PWS - a comp designed for short barrels that compensates, suppresses flash and directs all the blast forward.

The MadBull Airsoft version kits:
(Note: Thsi is Airsoft version which is made of lower grade materials and different dimension, Do not apply to real firearms.)
Including Handguard set, Outter barrel, Barrel nut, Compensator, and Non-functional piston decoration.
Not including upper receiver.