Thank you very much for responding so thoroughly.No doubt these catches are well machined and are a good after market replacement for defective or worn out standard parts.The thing is the purpose of the magazine toe is to provide a positive stop to magazine upward travel it can't go further than that,and because the catch is stationary it has to lock within thousands short of the toe's stop.The mag's dimensions have to be changed for it to sit higher.Thank you again,appreciate.
You're exactly right that there has to be a little clearance between the toe and grip or you'd simply never be able to insert the magazine into the well far enough to get it to catch. This is the same reason you don't want to use full-sized magazines in a compact frame, because the shorter grip won't catch the toe and stop the magazine's upward travel. But with the EGW catch you're just talking really about a couple hundredths of an inch, and even on my RIA with the EGW catch I've still got about .030" clearance between the toe and frame with the magazine fully inserted. It's hard to believe that something as little as a few hundredths of an inch really makes that big of a difference in feeding reliability, but when you're stacking such tight tolerances in the 1911 from the ground up those hundredths can indeed make an enormous difference.