Dumb question(s) time....again! I have been looking at M.D. Smith's reloading pages, and the differences in velocity using .38 Special brass and Unique. Iirc, he experienced about a 150 fps difference when the powder was against the bullet, as compared to when the powder was against the primer.
Shortly afterward, I read an article where another scribe advocated deep seating the boolit, with a corresponding powder weight adjustment, which he claimed eliminated the "problem".
His idea was to seat the boolit, crimping over the front driving band, instead of in the crimping groove, or crimping the boolit over the ogive, shortening the overall length of the cartridge.
My general loads use the "medium" powders..Unique, and Universal for velocity 900-1000 fps .My favorite loads are 5.5 gr Unique, and 5.2 gr. Universal. Will increasing either load by 1/2 grain change anything except velocity or reduce the "powder up, powder down effect? I am thinking of trying True Blue, or AA#5 in 357 magnum brass. About the same bulk? It's hard to find information about that. I'm thinking of using Trail Boss or HP 38 exclusively for my wadcutter loads.
My questions are:
1. Is powder position a real-world problem? I'm thinking of 2.4 gr. of Bullseye in .38 Special cases. Lots of air space, and the combination has won more matches than anyone can remember. Position sensitive? Unless competitors raised the muzzles of their guns before each shot, that would seem to be self-defeating, particularly during rapid fire.
If a person just HAS to do this, instead of going to all the trouble to recalculate (WAG ) powder charges, etc. Why not just deep-seat boolits in 357 brass, and use a starting .38 special load, working up as necessary?
2. Find a bulkier powder? Trail Boss comes to mind, but here desired performance may be a bit lacking.
3. Buy or cast a Keith-style SWC with the two crimping grooves, seat it to the front groove, and let COL go where it will?
4. My favorite loads are 5.5 gr Unique, and 5.2 gr. Universal. Will increasing either load by 1/2 grain affect the "powder up, powder down 'problem'"or change much except velocity?
Are any of the many extremely knowledgeable reloaders on the forum able to offer any direction? With so much information, it is a temptation to go back 40 years or so, look in the manuals, go by the TLAR (That Looks About Right) method, pick a load that's about mid-range... about .38 Spl. +P or slightly better...and load 'em up?
Thanx!