Anybody have any experience with Trail Boss and cast bullets in a 375 H&H? I have a bunch of 270 grain bullets and have had no success with 4759 powder. Any help would be greatly appreciated.

Hey Skinner,
I don't shoot a .375 H&H but I do shoot Trail Boss.
The Hodgdon web site recommends that you mark a case where the bottom of the bullet is when seated.
Fill to the mark with T.B. and weigh it, this is your max load!
70% of the max load is a start load.

Check the Hodgdon web site, Data page, Trail Boss Reduced Loads

OBTW, Welcome to the Fire!

Colodog
Thanks for the useful info. I'll try what what you suggested and report on my results.

I have played around with trail boss in a lot of different cartridges. Go with either a softer cast bullet or a thin jacketed bullet. Tried some thick jacketed bullets in my 475 linebaugh #1. Could not generate enough pressure to get the bullets to fill the rifling. Was getting keyholes and found a couple bullets with barely any signs of rifling contact.

I have always liked IMR 4227, 1500-1700 fps with the Lyman cast bullets I've used in 375 H&H. I shoot 4759 with a cast bullet in my 358 Winchester at 1900 fps; kind of a 200 grain 22 Mag load. Never played with Trail Boss in anything.

Use TB in 375H&H and 416 Rigby, works well and no need for fillers like some other powders for "light" loads. Just using it for cast loads so far.