BTW, I have ran across some 20-24 round extended length magazines for single stack 1911's in .38 super, on-line and at most any gunshow here in the valley. I haven't bothered to pick any up thou. For one they are no-name mfr magazines so I have no idea if the springs are worth a damn or if the feedlips are properly heat treated, if at all. Second, they are too long to be "legal" in my matches so I don't have any use for them anyway.
Ericf, i use the McCormick mags because they are the strongest and heaviest magazines i can find for my super. I've used metalform, Wilson, Colt and McCormick and i found that the Colt and McCormick last longer than the others. The Wilson's are well made but the plastic followers break regularly and ive cracked a body on one. The metalform ones also cracked near the feedlips. The McCormick and Colt mags (with a McCormick conversion follower and spring) last much longer than the others. Though i have had one of the McCormick mags crack at the feed lips.
Im very hard on my magazines, when shooting matches i have developed a little wrist flick to help throw the magazines from the gun and they fall directly onto the gravel, rocks and any steel shooting boxes or stage props, most often with up to 5 rounds still in the magazine. Ive been tempted to try some cheap magazines to cut and weld but im afraid id just be wasting my time with a magazine body that can't handle the abuse i dish out.