NH-GP100
NES Member
Trail boss is actually a pretty crappy powder for jacketed bullets. I know this because I've shot a ridiculous number of .38 Special rounds loaded with jacketed bullets and Trailboss.
If you're looking for a powder that yields consistent results and fills a significant portion of a .38 case, try Blue Dot.
I only use TrailBoss for lead cast, and that was because thats what dad uses for soft shooting CAS loads. That said, if you say I can get the same thing with Blue Dot then I am gonna give it a try next batch. I am getting from a~740 fps for 158 gr lead to ~840 fps with 127 gr lead. Should I expect about the same from Blue Dot?
I have been using A2400 for hotter .38sp / .38+P loads using plated bullets, I think my max was around 1100ish fps with 158 gr RN Berrys Plated.
I don't bother with jacketed in .38 loads, I save them for my hot .357 loads.