I may end up using the bullets in a new rifle in 357 mag caliber.
A word of caution about that. First, of course is making sure the bullets are flat/round nosed enough not to be a danger in a tubular magazine. If you're bullets are the ones I'm thinking of, it should not be an issue.
HOWEVER, overall loaded length COULD be. Some of the .357 lever guns (Marlins in particular) can be very picky about overall loaded length. It is possible to load ammo too long to feed from the tube magazine into the chamber. I've seen it happen.
A fellow I knew loaded some 210gr LRN slugs in .357 cases, stuck 2 in the tube, and wound up bringing me the rifle to take apart so he could get the ammo out of it, it was jammed tight.
Hornday XTPs are probably fine, but CHECK CAREFULLY in your gun, before you just load them up and find out too late there's an issue.
It was said a couple times, correctly, the 180s are heavy FOR CALIBER. It's not only the weight, I use Unique to drive 240/250gr slugs up to 1200fps in .44 and .45 cals, and could even go a bit more, but choose not to.
For .357, I don't shoot 180s, but 158s get 2400 or W296/H110 for full performance.