I got one of those promag 15 rd mags from guncity sale, it didn't work at all. The bx15 is great, has changed the rifle totally for my usage. I'm considering getting a few more for those occaisons when 15 at a time is not enough. I don't think putting a .22 into E configuration is worthwhile. Years ago I had a plastic 30rd mag for it, lot's of fun, but not worth the hassle these days.
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