I have a T/C Triumph, shooting 90g of BH209 pushing a Harvestor Scorpion 260 grain ballistic tip with crush rib sabot. Using CCI209m primers. My questions are.

The first shot is always a flier, gets better when I burn a primer before shooting.

After how many shots should I clean? I know it says no cleaning b/w shots, but still im shooting around 10 shots per range session. I mean I have a group good enough to kill a deer, but would like to get better. Any ideas?

Burn a primer, shoot a 3 shot group. Clean, adjust scope and repeat?