I have a chamber cast off to Jamison to help them get tooling made to set up for 577/450 brass. Last week he was working on his first 100 test cases. He should have brass soon.
Awful lot of us have used US BP loading techniques on the big Martini case and failed. it's a different animal.
If you can crack the nut, we are listening.
I use my MH for recreational shooting, informal competition and hunting.
For the past three and a half years the longest range I have had access to is 100 yards.
I get real excited when I do 2 1/2 to 3 inches with original military sights at 100.
Wipe between shots? You mean between strings don't you? Group shooting I will wipe after every 5 round group. No fouler for me every shot counts.
The Volunteer Match is 10 round strings, no wiping.
As far compression goes the only compression I have been doing is with the kapok filler. You don't have to add more powder toget compression,
I started with .6 grains of kapok over 85 grs. of Swiss FG. I slowly increased the kapok until I got to 2 grains. That is a lot of Kapok and I think I may be getting the same or similiar effect as compression.
I have also used Pufflon. Load the powder and fill the case up with Pufflon and compress that.
I then put a milk carton wad, 1/4" grease cookie of 50/50 crisco beeswax, two milk carton wads and a .468 480 gr. RCBS MH GG 20 to 1 as cast bullet pan lubed with 50/50 beeswax/neatsfoot oil. I seat the whole wad column so the first over powder wad is even with the bottom of the neck.
Of course I am not looking for the accuracy you are.
I want plenty of power f\or hunting. I have used my Martini's to hunt in Africa and the US. The list of changes load will shoot through a kudu end for end... meets one of Elmer Keith's criteria.