So my new MK12 (DPMS Barrel 1/8 Twist and 18" Rifle Gas System) had an issue recently..

 

 

The Troy 15" TRX Extreme decided to loose its 'heli-coil'.. and Troy is discontinuing that line for the newer Alpha design that uses a standard mil-spec barrel nut (happen to have a few sitting here).. and are sending me the Alpha 15" FREE..

 

I also had to cut off the Levang Linear Comp to 'un-pin' it.. (cost $40 out the window)..

 

 

so here she is naked so to speak.. I just did up the gastube with some low gloss 500' F black paint so it hides better under the incoming Alpha rail and put a YHM FH on for now to protect the threads (I live in PA folks)..

 

 

I also ordered up the KIES Blast Master Comp/Brake from JoeBobs.. almost the same as the prior comp with a slight shroud over the very end and beveled in.. ($48 total with priority mail and discount code.)

 

 

I called Troy yesterday and Jeff the return guy said there system has been down since Monday (my luck)...

 

Hopefully this will all time in with Range 14 to re-open in a few weeks so I can test it out with good ammo I got sitting here..

 

Stay tuned..

Well I got the Troy 15" Alpha Rail in today.

 

Was in clear plastic originally folks..

 

 

Much easier to install..

 

Heres the parts baggie.. and 3 rail sections it comes with.. (I still have my 3 rails from the defective Extreme)

 

 

Inside the barrel nut end.. notice the notch in the circumference of the rail and the 3 clips..

 

 

The Alpha uses 3 screws and clips inside at the 3/6/9 spots.

 

 

 

The tiny gap after installation is like the thickness of paper.. (which I just made tighter with practice)

 

 

Final cell pic after 1st install.. got to remove again to weld my Comp/Brake when it comes in Tuesday..

 

 

Would I pay $200 for this rail system.. I dunno.. Midwest makes a 15" that uses a proprietary nut and may be heavier..

For a replacement one (free) with slight upgrade and ability to remove and reinstall without fear of stripping out..

thanks for the pics. The metal tabs poke into the front of the stock barrel nut, and the angled shape makes the flange on the barrel nut wedge against the slot around the circumference of the tube? So anti rotation is just friction and the tab on one side? (Not that that wasn't the case before, but there was a lot more clamping surface in the old design).

I dunno for sure how it works.. but it feels pretty darn sturdy.. not sure if its a push/pull or wedge going on..