New .44 caliber Brooks mold.

[Kurt]

Jim,

Those groups are looking good with just a starting load.
I used to swage bullets and I still have the Corbin tools, both Corbins.
Most of those dies were cup based as well as flat base and man I looked at a lot of snow bank bullets to see what goes on with different ways to load and alloy that works best.
The thing with cup and dish base bullets, dish base do perform better than the cup base.
One thing to keep in mind is that the larger the diameter the more critical it is to use a thicker and harder wad as the diameter's increases. The .50 caliber that I used to shoot the most was a big problem shooting a cup based bullet even tucking the tail into the cup but the skirt was fragile and it created a problem with the lube getting pushed past the wad under the bullet and the lube would glue the patch folded under or twisted, especially just folded under and the patch would ride down range with the bullet.
But it also created another problem. The soft skirt using a hard .06 wad under the bullet would just the thin skirt wall forward creating wrinkles that would trap the patch onto the shank and carried down range. This was more of a problem when I used to wet patch the bullets then dry patching.
Here are some of the .50 caliber I still have a photo of. Notice the wrinkles and one had a gas leak.
With the smaller diameters bullets this will usually not be a problem with a good wad. Surprising a .06 cork wad under the bullet worked well protecting the skirt and I never found one in the test bank at 100 yards down range more was a patch stuck to the base.
But cork wads can create other issues.
I also tested these cup based bullets without using a wad seating the bullet right on the powder would work well but the finer 3F would make less granual impressions on the base then the 1F but groups held tight.