I went to the range today. I'm all set with my smooth bore ghost ring barrel set up. With Remington Foster style slugs I'm shooting right around 4 inch groups at 50 yards. I'm happy with that.
I still have some work to do with my rifled cantilever barrel set up. I was only shooting to see which slugs shot the best. I wasn't to concerned about my point of impact. I shot an amazing 3 shot 2 1/2 inch group with Federal's 2 3/4", Vital Shok 3/4 oz. Barnes Expander Tipped Slugs. That's the best group I've ever shot with a slug gun.
I shot 6 different 2 3/4" slugs, The Federal's mentioned above, Fusion slugs, Lightfield slugs, Hornady's SST slugs, Remington's Ultra Bonded Core-Lokt slugs and their AccuTip Bonded slugs. The Federal's were the only slugs that I was happy with. The rest wouldn't shoot any better then 4 inch groups at 100 yards, with the exception of the Lightfield slugs, I didn't shoot them at 100 yards, only 50 yards, so I don't know how well they are at 100 yards.
The other slugs not shooting as well as I wanted could be from my barrel getting dirty I don't know. I shot the Federal's about halfway through my shooting session. I was switching back and forth between my 2 slug barrels and my Marlin 336C 35 Rem so the barrels were cool.
I'm going to clean the whole gun and shoot some more groups and set my point of impact to zero at 100 yards with the Federal slugs.