I've been infatuated with the Mk12 Mod 0 rifle since I first laid eyes on one many years ago. I've put together two of them, one is complete and the other is awaiting a scope I've got on order. I had an AR pistol I had put together with a 10" Krieger barrel which was made from a cut off section from a blank I had on a bolt gun. I thought it would be more fun than it was so I decided to change directions. After some thought and a bit of research to determine if this might work I went ahead and started gathering the components to convert the pistol to something a bit more functional.
The Mk12 Mod 0 and Mod 1 run an 18" barrel and the Mod H runs a 16", I decided to put one together with a 14.5" barrel. I bought a used PRI Gen 3 hand guard, cut approx 3" off of the end and turned the end cap off on the lathe so it could be put back on the now shorter hand guard. I shortened the top rail to work with the shorter hand guard (and the Mod H rail) by cutting several inches off of the back and moving it rearward. I had to drill a few new holes to get the shortened rail and relocated bottom rail positioned where I wanted them. Zack at ZR Tactical Solutions also turned down the muzzle end of the barrel for the AE collar and drilled, pinned and welded the brake on to bring it out to a legal 16 1/8". I found a vendor online who still had a black Rock River Arms Entry stock on hand and when used with the Law Tactical Folding stock adapter the length is perfect for me, right where I run my collapsible stocks.
It turned out exactly like I'd hoped and is near perfect for what I wanted (truck & bumping around the farm gun). I'm watching for a used A.R.M.S. #40L to finish it out.
The Mk12 Mod 0 and Mod 1 run an 18" barrel and the Mod H runs a 16", I decided to put one together with a 14.5" barrel. I bought a used PRI Gen 3 hand guard, cut approx 3" off of the end and turned the end cap off on the lathe so it could be put back on the now shorter hand guard. I shortened the top rail to work with the shorter hand guard (and the Mod H rail) by cutting several inches off of the back and moving it rearward. I had to drill a few new holes to get the shortened rail and relocated bottom rail positioned where I wanted them. Zack at ZR Tactical Solutions also turned down the muzzle end of the barrel for the AE collar and drilled, pinned and welded the brake on to bring it out to a legal 16 1/8". I found a vendor online who still had a black Rock River Arms Entry stock on hand and when used with the Law Tactical Folding stock adapter the length is perfect for me, right where I run my collapsible stocks.
It turned out exactly like I'd hoped and is near perfect for what I wanted (truck & bumping around the farm gun). I'm watching for a used A.R.M.S. #40L to finish it out.
