Well there are not much to choose from in .177 slugs, in general they just come in 1 size VS others you might see in 2 diameters.
I have only shot slugs in my Maverick ( 700 mm barrel ) and my Vulcan 3.
Both do fairly fine with the chocked barrels, but i am going to just shoot pellets in the Vulcan 3 moving forward, even if the V3 and its 530 mm CZ barrel are hanging with the Maverick just fine
I use 3 and 2 " splatter targets i put on cardboard and then put out at 75 - 100 M, and if the wind are not too bad i can generally keep all my shots within those targets ( Denmark are quite windy much of the year hence why we are the masters of Wind turbines )
I have not yet found a super slug, but 12.5gr NSA and 13 / 13.43 gr JSB KO / Zan slugs are what i shoot most, getting 15 -16 and the top dog 20 gr slugs up to speed are no problem, but accuracy are dropping on those.
I am hoping my new Heavy liner will change that, even if its twist rate are the same as the old barrel, then the rifling are not the same.
I like to be able to shoot the heavier ones even if i dont expect to do that very often.
But my Maverick have been in the shop now for a month with the broken cocking handle,,,,,, fortunately the weather have been miserable so i have not been missing shooting.
Viking airgunner and Soren D are way ahead of me with the slugs.
Also on uploads to youtube.