The lurker speaks... I have more info.
Received a T&E unit in September at out police department. We installed it in a like new Colt AR-15A2 Government Carbine. I have since put 3000+ rounds through the converted rifle (1500 rounds as part of the T&E process, a tactical rifle course, and two qualifications.)
Installation was extremely easy and is well documented on the internet if you want details. We received an earlier version with a replacement gas key; the retail version that is shipping now with a one piece BCG. M4 hand guards were included. I hate Mr hand guards and intend to modify the heat shield in a Magpul MOE hand guard to work with the conversion.
The conversion has operated flawlessly. No failures in 3000+ rounds.
The weapon was not cleaned in the first 1500 rounds for the T&E. I admit that I was shocked when I split the receiver. The weapon fires CLEAN! There was nominal fouling in the receiver and the BCG was exceptionally clean. The fouling encountered in the receiver group was a very light coating of carbon (probably deposited at the extraction operation), the normal tiny grains of brass generated in the operation of the M16/AR15 platform, and dust from the range environment. Cleaning the rifle was simplified exponentially.
I have never had to clean the gas piston assembly and there is only a hint of carbon "spray" on the hand guard heat shield directly above the piston. Additionally there was markedly less gas "in the face" as any gas escaping the piston assembly does so underneath the hand guard.
The bolt was cool to the touch even after several magazines at rapid fire. The gas block/ front sight assembly and hand guard was not noticeably warmer when using this system. I have heard, anecdotally, that the gas escaping the piston under the hand guard can cause heat blooms in thermal sights, however we do not use this technology and, of course, noticed no adverse effect when the rifle was fitted with nigh vision behind the EOTech. No discernible difference was noted in accuracy, recoil, flash or report.
As I mentioned before, the rifle was like new. It had not been issued and had less than 100 rounds through it. The inside of the upper receiver had no wear on it at all and was fully anodized. We have watched it closely and it currently exhibits no wear whatever after 3000+ rounds.
While it is not a consideration since Osprey went with a one-piece BCG with the final version, we have seen no loosening of the gas key replacement and it was checked with a torque wrench and still maintains the proscribed torque setting.
Loads used were Winchester 55 grain FMJ, Black Hills 55 grain FMJ, and Hornady 55 grain TAP Urban. Magazines were Lancer 20 round, Colt 20 round, U.S. Military issued 30 round, and Magpul P-Mag 30 round. No drum type magazines were used. No sound suppression devices were used.
Based on the results of the T&E, the firearms program at our department has suggested retrofitting all of our Colt AR-15 A2 Government Carbines with this system. The suggestion has been taken under consideration by administration and no decision has been made yet.
I plan on purchasing one for my personally owned carbine. Of course your mileage may vary, but I hope someone finds this information useful in making a purchasing decision.
