I have never had a problem on my limited with the Tangfo grams setup, using a lee U die, and loading to 1.175.. usually much longer then that is when I run into problems. Only problems I have ever had with the mags are when they get a little bit of dirt in them they tend to act up.
Leo
Edit: thats with once fired brass. I shoot anything but speer. usually Federal and Aguila.. thats using Clays.