Hey reload68,
Cast bullets work just fine in micro grooves. Check out lowveldata. I just traded mine, purchased new in '75, for a Cowboy. Mine had a speed limit of about 1300 fps with lead.:hmmmm: It liked 1150 to 1200 fps best. 300 gr for 50 to 100 yds, 350 gr for 100 to 200 yds, and the 405 gr for out there a bit. Loaded the lighter bullets for less recoil. Both in wallet, and on shoulder, LOL. Check out some of Wind's postings and vids. He pretty much has the 45/70 lead bullet combo sorted out. There is a gentlemen down near Pittsburgh, PennBullet, who makes some excellent bullets, and ships quick. Get a hundred of each, see which shoots the best, then buy your molds. Hate having a mold for a pill the rifle doesn't like. Make sure you trim your brass to a uniform length, and use a die that applies a nice roll crimp.:biggrin: I have had good success with the Redding crimp die, while others have had success with the RCBS Cowboy Die. The verdict is mixed on the Lee FCD. With the 405's, crimp is important. You will notice vertical stringing if your crimp is not uniform. Also, Micro Grooves do not seem to lead.:biggrin: Hope this helps, good shooting.
Merry Christmas,
Mark
Duty is the sublimest word in the English language. Every man should desire to do his duty, no man should desire to do less. Robert E. Lee
