Unless you get lucky with your gun/barrel, this is absolutely correct. I think the SSTs are the most universally accurate, but I have heard of people complaining of their performance on deer. I'll take a better-performing bullet any day over one that shoots cloverleaf groups. With that said, after trying many brands of slugs, I found that my gun grouped the Remington Accutips reasonably well. I have fired one shot at a deer with these and I have one kill. The buck went down immediately and didn't even budge.

Now, I find it odd that your lottery hunt is shotgun only and that they do not allow muzzleloaders. Where I hunt, I have never seen shotgun only with no muzzys allowed, but I have seen it the other way around. If I were you, I'd call up the dept heading the lottery hunts and verify that you cannot use your muzzleloader before messing with buying a variety of slugs to test. It will save you a ton of $$ on ammo, and you may be able to return that (hopefully unused) Encore barrel.