I haven't got to shoot the HPBT but I shoot the 55 Tipped version in a 22 Dasher, 14 twist Hart. They are more accurate than the 55 BT and the 55 VMAX, in that gun. The VMAX seems to be a bit more explosive and the BT seems to be be a bit less. But that is subjective.
I'm a fan of those bullets.
When I get an opportunity to buy some of the HP's I'll jump on them.
