When using slugs you're ahead of the game with faster twist barrels for mediums and heavies for higher bc's.
The more energy you want on arrival tends to favor larger calibers. There is also more sight picture upset. More air is required. Can cost more. Sometimes higher BC, and these hit hard.
My AGT Vulcan 3 was a great choice for 60gr Altaros Queens. Had it tuned by Derrick Wall and GTG ever since. Very dependable and precise. I think it's a 17 twist.
99 fpe.
The 22 cal Skout EVO is also great with 32.3 grain Altaros Smooth. This is a 15.75 twist. 49 fpe.
Huge difference of energy transfer as well.
But the EVO is more forgiving to shoot and 30 rounds on tap, plus higher shot count per fill, just makes it a more fun experience.
I can still hit smaller steel at 250y fairly easy with the EVO though it's not moving the steel much.
Just all around I enjoy the EVO more but the V3 excels the farther the distance increases.
The EVO is easier, or shall I say, more convenient to tune. Even I can tune it and 22 cal with slugs has worked out very really well.
I haven't tried Altaros 40gr King's in the 900's yet which will bridge the gap between those two guns and power levels.
Could even try the 56gr but it'll be single loading only like how I do with the V3 because I haven't modified a magazine for these long slugs.