I have been playing with my GP 100 for around a year or so , and have yet to find the ( O that's nice ) load out of it . I have tried a couple different wad cutters out of it as well as the RCBS 150 and saeco 158 gr swc with out getting a tingling felling of satisfaction on target . As of yet all my loads have been very mild probably not even up to 38+p but I think I want to try speeding them up just to see if that helps . I just so happen to have a few pound of w 296 on the shelf that seems to not be going away fast enough in my 410 loads . Now with total honestly I'm not that good of a pistol shooter but I have shot decent shooting guns in the past so I kinda expect better than what I have been able to achieve . My cylinders are true to fit .358 and I have no problem with leading but lacking in on target is a problem .