Plans changed so I had time to load up some initial "cowboy" loads and head to the range on Sunday. Used a 200 gr. RNFP bullet from Western Nevada Bullets and TiteGroup. Started out with Win. .44 Spl. brass and 4.5 gr., then went to 5.0 gr. Then loaded some Rem. (UMC) .44 Mag. brass with 5.0,5.5, and 6.0 gr. Took the Western Marshall and the '92 Rossi and headed to the range.
Results: All shot @ 15 yrds w/o sandbags, but forearms rested on a carpet covered block, 2-hand hold.
.44 Spl. cased loads - Both loads went about 5" for 10 shots, centered about 3" rt. and 3" low of POA. Same loads out of the Rossi '92 were less than 2", about 1" high.
.44 Mag. cased loads - significantly better, with the first load (5.0 gr.) going 10 shots into 2", about 2" rt. of POA. The '92 put 5 into a group 3/4" high by 2" wide 1" low of POA. The other loads started to open up a bit, but nowhere near what the .44 Spl. cased loads were.
All in all, I'm pleased with the Marshall. Now I just hope I can get a Vaquero that likes the same load!