COLT - AR6951 9MM Conversion Unit Adapter

I had bought a demilled colt mag kit came with every but a new lower. And instead of using the original mag conversion I wanted a new colt one to replace the original one so I could get the holes in the receiver in about the original position without having the be exact and risk ruining the new psa lower. My original one had the last round bolt hold open in it and the new one had the pin hole and milled for it so I removed the original one from the original block and installed it in the new block. Everything works great couldnt ask for it to work any better then if colt had put it together themselves. Very happy with how it turned out. Great fun accurate pistol.

Used magazine catch to keep in place while drilling , worked great. Installed roll pins two ,one in front, one in rear of receiver ,functions perfect .500 rounds not one malfunction . I love it ! The gun techs at Brownells are the best ! Thank you The Brownells colt style 9mm magazine work great as well !

I bought this and have been using it with my 9 millimeter Luger AR-15 upper. It works great with full metal jacket brass ammunition. I think I have fired a little over 125 rounds through it without problems using twenty round ASC 9 millimeter magazines. It does not hold the bolt open when you fire your last round out of your magazine which I really do not care much about. The one thing I do not like about the AR6951 9 millimeter Conversion Unit Adapter is to make the conversion permanent you would need to drill a small hole in your AR-15 receiver (minus one star for this). I did not bother with any hole drilling and it makes magazine changes more difficult as the conversion unit part will come out of my AR-15 magazine well when I push my magazine release. I just use it for target shooting and training anyway. Not really much of an issue when you have nineteen to thirty rounds to shoot. 9 millimeter is a great round to train with for an AR-15 for about 60 yard distances and closer. It is much cheaper to shoot than .300 AAC Blackout or 6.5 x 39 Grendel ammunition. You could use a 9 millimeter carbine in self defense but I generally prefer a more powerful round.

Very happy with the fit and finish of this unit. However this unit is supposed to utilize a bolt catch lifter that eliminates the need for the Colt extended bolt catch. It not only is not included with this assembly, but Brownells does not carry it either. I will search for this part, but in the meantime, I will have to purchase the 9mm Bolt Catch in order for the last round bolt open to work. It looks like it should work, but we will see.