cayugad

The only thing I do with powerbelts different then you is.. I do not use pellets and before I seat the powerbelt, I pull the plastic button off the bottom of the conical. You will note a small lead spike coming off the projectile that the plastic button fits back on to. I put a small dab of lube, oil, spit, anything I have around, and then replace the plastic button. I feel this assists the powerbelt is shedding the button faster and giving me better accuracy.

One other thing I am wondering is, if you are shooting these three powerbelts in a row, and the third one is always the flyer, do you suspect that the barrel of the rifle might be heating up and causing perhaps a variation of the powerbelt spinning in the bore? Or perhaps as you noted the fowling is getting worse, but since you said you are swabbing between shots, I wonder if before the third one is loaded perhaps an even better job of swabbing might be in order.

Next time you shoot, try letting the rifle cool down longer between shots. And really concentrate on the swabbing technique. It sounds like you have an excellent setup. I am sure some of the Omega shooters will have a better answer then I...

Good luck with the rifle. Shockwaves really do shoot well out of most of the Thompson Center rifles.