Sorry for this late follow-up post, but I did some additional Longshot testing on memorial day to see if the SD/ES numbers will improve with higher charges. The conclusion is that the SD/ES numbers did improve, but it is not on par with some of the CFE Pistol loads that I tested with lead bullets.
My accuracy testing did not go that well, but one thing I realized was that the higher velocity magnum loads are not that comfortable to test from my rest. After testing these loads I changed to using my rang bad as a rest, which meant a more natural hold, and subsequent better recoil management. I still have 10 of these RMR 158gr bullets to test, so I will do one more test, using my bag as a rest, and test them at 15 yards.
Even with the problem I was having testing from the rest, two of loads did not test that bad. I am going to load another 8.2gr and 8.3gr loads for my final test with these bullets using Longshot.
Some of the loads are short 1 shot with the chrono. It seemed not all registered. It was early in the morning, which maybe attributed to the missing reads.
Here are the results:
357mag
COL: 1.580"
RMR, 158gr, HMRNHP, Longshot, 8gr, WSP
Average: 1022
ES: 123
SD: 53.9
Force: 366
PF: 161
Velocities: 946, 1025, 1049, 1069,
Grouping: 1.93"
357mag
COL: 1.580"
RMR, 158gr, HMRNHP, Longshot, 8.2gr, WSP
Average: 1045
ES: 56
SD: 22.8
Force: 383
PF: 165
Velocities: 1031, 1045, 1039, 1029, 1085
Grouping: 1.33"
357mag
COL: 1.580"
RMR, 158gr, HMRNHP, Longshot, 8.3gr, WSP
Average: 1074
ES: 45
SD: 17.1
Force: 405
PF: 169
Velocities: 1098, 1084, 1072, 1053, 1067
Grouping: 1.33" (4 shot .70" grouping and one flyer)
357mag
COL: 1.580"
RMR, 158gr, HMRNHP, Longshot, 8.4gr, WSP
Average: 1083
ES: 57
SD: 24.6
Force: 411
PF: 171
Velocities: 1048, 1088, 1105, 1092,
Grouping: 1.87"