Whats the difference with the semolina? I've being using Whitworths as it's available at most supermarkets and I found that by measuring into phials before loading I can get the balls seated at the same depth.
ROA, 20 grains Swiss 2(measured phials), cast ball from what ever lead I can source, home made felt wad lubed with 60/40 lard Bees wax(same mix for my Martini lube) and I'm getting pretty good results.
No problems with fouling and comes up clean after a putting into an ultrasonic cleaner.