In my, admittedly clumsy, attempts to search for information on the subject, haven't been able to find anything about which mag extensions/springs work best with Glock 22s. Looking for a +5 if there is an acceptable one. I tried a strike industries extension, but, in spite of their excellent customer service, I couldn't get it to feed reliably. I went through 3 replacement mag springs and I couldn't get any better than a 50% failure to feed rate. I suspect that the .40 is more demanding in the mag spring department.