Hello all,
I wanted to put my thoughts together and create a resource for others while they’re still fresh from this little project.
- This was not a simple drop in installation.
- The steel upper and lower were not correctly mated from the beginning; I could not pass the included takedown pin through the two of them because the holes did not match.
- I did not use the metal upper insert from the stock M11, the kit seems designed to not use it.
- I had to file down the barrel retaining block to get it to fit into the upper; I tried to take equal material from each side by doing 10 passes on one side and then flipping it over and doing 10 passes on that side.
- I had to taper the pin that retains the outer barrel because it would not fit into the steel upper. I did this by putting it into my dremel and tapping it against a file at an angle as the dremel spun the pin.
- I had to hold the assembly together (with the bolt cocked back to relieve spring tension) and then dremel through the main takedown pin path as the upper, lower, and barrel/hop up block were not lined up. This prevented the takedown pin from going all the way through to keep everything together. I had to take a considerable amount of material off and change dremel heads multiple times. There seems to be excess rearward pressure from my current alignment, but it is good enough for me and everything functions fine. I may try to fine tune this later on, but am worried about taking too much material away.
- I had to file the rear of the magazine well to get it to easily accept factory magazines; I tested this with two magazines.
Overall I am happy with the final product, but it was much more involved than I anticipated, and I am very happy I had the tools on hand to resolve the issues I ran into.
Hopefully, this helps others in the future.