I have used the powerbelt airo tip bullets for a few years... the following is what I have found out:
1. They are very accurate out to 100 yards... beyond that they do not group as well.
2. They have excellant penetration but limited expansion.
3. I had tried the hollow tip and they did not group well in my rifle.
4. This year my friends and I experimented with the TC Shockwaves... we were able to get them to shoot a 3 inch group at 150 yards... using 100 grn of powder.