Well, in the case of bullets, etc - small sprites, a blitz linepick usually works fine. I've heard pretty good things about nuclearglory dll.
If your bullets travel in straight lines, you can just do a blitz linepick from the weapon outwards, to the weapons range and then processed whatever is picked (assuming a positive pickmode). If your bullets are slow or have gravity applied, you can do a pick from the last position to the new position to check for collisions.
If your bullets travel in straight lines, you can just do a blitz linepick from the weapon outwards, to the weapons range and then processed whatever is picked (assuming a positive pickmode). If your bullets are slow or have gravity applied, you can do a pick from the last position to the new position to check for collisions.