Tested 4bore with a double ball load of 1250 grains weight,
Used 100gr Blue Dot under 250gr of RE17, with card and
one fiber wad. 2600 fps. Recoil not bad, just brisk.
Used turned brass cases with shotgun primer, and cases
still didn't expand base. just size top..
Running about 23-25,000 psi.
The light ball load in above post
about 16,000 psi.. Ed