I had a #225415 during my early years of casting. I didn't know much about casting or managing cast rifle bullets back then, and gave up on smallbore casting for several years. Time went on, and RCBS 6mm and 22 moulds showed me that small bores could be made to do good things IF YOU PAID ATTENTION TO BUSINESS. 22 Hornet, 223, and 22-250 have started behaving themselves with castings for me--just in time to have them disallowed for hunting in my home state. It's a &^*% conspiracy.
Lyman #225438 does some decent work in all 3 calibers for me, and the RCBS #22-55-SP shows promise in 223 and 22-250. That smaller Lyman Loverin was instant goodness in 22 Hornet, and stayed that way in 223 and 22-250. Some dated writings by Mike Venturino was a BIG HELP in 22-250, Rick Tunell/Buckshot gave me copies of his articles that I turned into results. The #225438 is an older Ideal 1-cylinder model, and it takes a while to fill a 1# coffee can using that tool. In 92/6/2 it casts just a couple tenths under .226", and gets "full clean-up" in a 'true' .225" H&I die. Same deal with the RCBS mould, nice and thick.