Pistol is a Ruger Old Army, so far I've tried:

semolina - tends to clog up in the flask/nozzle on even slightly damp days

cous-cous - perhaps too granular, doesn't clog but difficult to "throw" a consistent amount, also compresses quite alot when the ball is rammed home

what else have you tried that works?

Does it come down to the brand - is Waitrose semolina superior to the Tesco product ?

regards
Nigel