As I do more exploring and research into my Black powder cartridge shooting I’ve become fond of reduced loads and using COW as filler to reduce recoil and save precious black powder!
My main cartridges are 42 berdan and 11mm Gras. I like to reduce the 42 berdan down to about 65 grains from 77 with my 385 grain bullets. This has worked well for me, but I read somewhere that filler shouldn’t be used in a bottleneck case as it can “ring” a chamber. Is that hocus pocus? My 11MM Gras dies actually say to use it!!! I’ve never heard of this actually happening? Seems silly that some little grits can ring a chamber but not a massive wad like the original 577-450 martini used???