you'll have to do a bunch of testing to see if there's a slug your gun likes.
+1, it's really individual to each shotgun. One shotgun may like something that another shotgun absolutely sucks with. It's not cheap trying to find out, but it's worth it in the long run; you don't want to be guessing about your slug choice when the time comes to shoot. If you're primarily a ML hunter, you should already understand the general range limitations you'll be working with.
My personal sabot slug choice are Winchester Supreme Elite Platinum Tips, which I don't think they even make any more. They're my choice simply because that's what my 535 shoots the best, bought a bunch of them a few years ago and have been slowly shooting my supply up ever since.
---Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away.---
---Enlightenment is the ability to take infinite pains---