I talked to the developer of sniper, and he okayed the following technically-not-raw due to poor word selection combo. Apply bounding shot and piercing shot to a single deadly shot to pseudo full attack, but with your deadly shot stuff. You can also use that to bounce an arrow around a room and hit the same person multiple times.

I just wrapped up a giant slayer campaign where I was playing a cross bow wielding sphere inquisitor. Between enhancement and alchemical coating, studied target, and bane, I was easily doing 180+ damage on a deadly shot. Damage that I never missed one because even a nat 1 had enough bonuses to hit a giant. Then it would piercing and bounce and hit them again.

Of course, I had retrained out of barrage because I was doing 450+ per round around level 10. But honestly, that’s stupidly excessive.