x39 short magazine question.
Sorry for the dumb seeming question, but the main problem I see guys griping about with x39 rifels is the magazine. Looking at my mags, the feed lips, etc look the same as a regular AR mag, it's just the curve that seems different, so here's my question:
Will a x39 gun function and feed rounds out of short .223 mags, say from 5-20 rounds [of .223]? I have a couple of 5 rounders that seem like they would work, but I am a little leery of cycling live rounds in the house, and I don't have time to hit the range today. If yes, how many rounds will fit in a GI 20, or a commercial 5 or 10 round mag? Is there anything I should look out for when I do take this to the range - like Pmags not working or something odd? [I figured out that Pmag 20's dont work in my .458 SOCOM very well].
Since magazines are typically the weak link in the 7.62x39 AR story, the answer in the case of short magazines is about the same as in the long ones.
The feed lips are not the only variable that affect the performance. The ribs that control the case as well as the follower have as much to do with the performance as the lips.
You can control the spring preload range to be roughly the same for a spread of rounds so the difference isn't always just due to the springs.
Some short magazines designed for 5.56 or other rounds can work, but the best ones actually have specific dimensions to get the best results.
Play it safe and either use dummy rounds or wait till you get to where a discharge is no big deal.