All right! I'm officially a reloader! All 20 rounds fired and functioned perfectly!
Have to admit I was pretty nervous firing that first shot ... kept thinking about Wobbly's old comment about tying the gun to a tree and pulling the trigger with a piece of string. I was watching the slide to make sure it functioned and case ejected on the first shot, so I missed the target entirely, but next 4 rounds made one hole in the target at 7 yards. In the picture below, top circle target was shot with my normal Blazer Brass 124 gr factory ammo, bottom target is my reloads with 4.4 gr HP-38, Winchester SPP, RMR 124 gr RN FMJ.
20161014_RELOADS_4_2 (1) by
baldrage, on Flickr
4.5, 4.6, and 4.7 gr also functioned fine, but targets did not turn out as impressive, just my typical scattershot 4-5 inch grouping.
Shot all of them free-hand, about one round/second, and I was more concerned about them functioning properly rather than trying to judge each one for recoil and accuracy. I
think 4.4 gr felt pretty soft on recoil, and 4.7 was a little snappier, more like factory ammo, but couldn't say for sure. Nothing noteworthy to say about 4.5 and 4.6 gr. I will load up another 10 of each powder charge, and do a proper accuracy test from a bench rest next time I go to the range.
For now, I'm very happy that the months of research and weeks fiddling with the SDB to get it dialed in paid off. Thanks Wobbly, Painter, IDescribe, 1SOW, Boris_LA, and others who have taken the time to comment/answer my questions!