I'd go with jacketed if I were you.  I've tried cast in a few matches, works great for the first string, then accuracy deteriorates from there.  My last attempt was an 80rd match with my K31.  By the time I got to the end of that match, I had a heck of time getting my brass brush down the bore and the yellow brass was silver by the time I was done.  I was using babbitt bullets, a bit harder and tougher than lino. I therefore came to the conclusion that there was a reason those cast bullet benchrest shooters were cleaning their small artillery pieces after each string.  The majority of them are lino shooters too.