The funny thing with the 15.5 NTX is it cost more for a box of 100 component bullets than it does 100 rounds of 17 Mach 2 with the same projectile, ridiculous. I have a 17 Hornet, and mine shoots the factory 20's and 15.5's amazingly well. The speed of the 15's really catches your eye, but if you run the ballistics on them, the 20's match the 15's speed at 75 yards. Anything further than that and the 15's are a lot slower than the 20's. So if you're looking for on target effect at 50 yards with your Hornet, shoot 15's.
Around here it's likely to be starlings and the odd magpie. No gophers to speak of, that are very local.
I see, speaking of component bullet prices, that Midsouth Shooter supply is selling bulk 20 grain hollowpoints for ~$45US for 500. Maybe they will be available to us, if the changes to the export regs pan out to a more relaxed border.