Variety hey . how about going back to good old 25 mil kills only , where skill counts not set up and piddling about checking that your zero has not moved a fraction cos it has got hotter or colder ? down with 15 mil kills brothers . bring back the luddites . smash the machines ( 15 mil variety ) you know it makes sense ??? HOLLY
Why not go back further, i can remember 45 + 50 ml kills, i think even you may get them
15 ml work if you set up correctly for accuracy and are not relying on luck with "Big" kills.
Mini kills = accuaracy
Big Kills = Luck!
25ml out to 40 yards in the right conditions perhaps? just one or two per course?