I agree with Jim Watson on the Clay line. When I started out (When things were hard to find) I stumbled across some Universal.
I had read references to Clays and Clays Universal (Also seen referenced as Universal Clays).
There was no other experienced reloader to talk to and the guy at the shop where I got it was "Pretty Sure" they were interchangeable.
I wrote to the company and either I was not clear in my question or the guy who answered me was just as confused, because he said they were interchangeable also. (I can not find the e-mail now, but I did post it here awhile back.)
I still felt there was something wrong with the answer I got from the company and the guys here on the board cleared it up.
I prefer the number system simply because it is hard to screw up a number.
I was doing things bass ackwards before. Buying powder and then looking for loads. I have sense learned to look for loads first and then buy the powder.
Inside Every Bright Idea Is The 50% Probability Of A Disaster Waiting To Happen.