Believe it or not, the T/C CheapShot non-ballistic tipped hollowpoints group well and expand well out of my Omega .50. I've also had luck with the Hornady SST's but I think they are pretty much the same bullets as the SW's. Please correct me if I'm wrong. I never did like the PowerBelts. I get poor groups with them out of my omega.
I usually use a 240gr .45 sabot with two 50gr 777 pellets.... deadly load for my rifle. I have also used the 200gr. shockwaves but they seem a little too light. The non-ballistic tips seem to expand better on impact, so I get a good blood trail though the deer I've tagged usually drop within 20yrds. I also seem too get better groups with the non-magnum bullets, but they may be an option also. Your gun may like them. Hope this helps....