Just going on what the guy said I think he is a member here too at greybeards and he is a member at the castboolit site where he posted the info hey if it works why not. This is a other guys reply using the buckshot
Waksupi has the answer for RB's though. I know 2 guys shooting 32's. One is one of our match competitors and he does a fine job using that shot. The other guy is an old Rondyvooer from way back, and a BP shooting fool. His favorite rifle is a 40 cal on it's 2nd barrel and he's had to go to thicker patches awile back.
He was shooting a 32 one day next to some guys shooting 22 Win mags. His 100 yard targets would have given them a run for their money.
Buckshot
For about 10 bucks a bag which is what I can get it for anyway I will give it a try if it shoots great. If not I have some Buckshot for some shotshell reloads. For that price I cannot afford not to try it.