I had my #358429 and #429421 both opened up professionally. Accuracy was improved. For some reason, my 1960s unaltered #358439 HP will outshoot the #358429. So does the H&G #51 160 gr. SWC. That's the one I use all the time for .38 Sp. and .357 loads. I'm not much on the Elmer Keith mystique.