As some of you may already know, I own a 22lr conversion kit for my AR15. When I bought the kit it came with one 25 round magazine and I went ahead and bought a spare. With the 25 round magazines however, I found it difficult to use the bipod; the magazine rested on the table rather than the butt of the rifle. Sometimes I had to extend the legs on the bipod just to achieve proper sight alignment. I wanted something shorter that was still compatible with my conversion kit.
The Black Dog Machine 22lr X-Form magazine was the solution. It came in several different capacities and colors, but I opted for the shortest they had (10 rounds) in black since I planned to paint it anyway. It was reasonably priced (in a time when gun parts and accessories are hard to come by) and it shipped much faster than I expected.
At first glance it isn’t all that impressive. Its very lightweight (the magazines by CMMG were weighted) and made of pretty thin plastic. But that is far overshadowed by its exceptional performance.
Loading the CMMG mags is a pain. It takes forever to drop 25 22lr rounds in them and the spring is extremely firm. With the Black Dog magazine, that is not an issue. The spring, while firm, is easy to depress enough to load. Even loading the magazine to full capacity is easy and there’s hardly any resistance. You would expect a light spring to not feed properly, but I’ve yet to have a fail to feed (granted 22lr rounds aren’t as large as other calibers).
Another pleasant surprise was that the bolt catch worked. According to the website and some information I found online, the Black Dog magazines didn’t hold open the chamber when using the CMMG conversion kit after firing the last round. This information was wrong in my case; it works very well. It even locks into the receiver better than my CMMG mags which occassionally require extra effort to fully insert.
Overall I think its a fantastic product. The 10 round capacity is much better for my needs. 1) It keeps me from blasting through as much ammo. 2) It let’s me use my bipod without the magazine interfering. 25 and 30 round mags are great and I very much enjoy the ones I have, but for target practice and general use, a smaller capacity magazine will do the job for me most times.
If you’re looking for a magazine that will work with your CMMG 22lr conversion kit, definitely consider one by Black Dog. You will not be disappointed. My only regret is buying just one . . .
** Updated on 4/9/13 – Added pictures and links **