After many years of setting aside my shotguns I'm working with them again. I am shooting through a pile of old ammo and need to replace it. Looking at Federal Truball for the slugs. They claim 2" accuracy at 50 yds... In the past I've used several standard Foster types and Brennekes. Any experience with these Truballs?

They are good slugs in my experience - my smoothbore 870 and model 11 shoot them well.  I don't get 2" accuracy, but I shoot open sights and bead sights on  the model 11.  If I hold well they do group better than the generic Remington for sure.  They seem to hit hard and penetrate deep.  Coyotes and deer agree.  I have a bunch of Brenneke 2 3/4 "magnum" slugs too (got a ton clearanced years ago_, not sure if there better than Brenneke magnums but seem to hit with authority.

I have hunted with my cylinder bore 590 and they shoot better than any other foster slugs for me.

I hunt with the deep penatrating ones. I can keep 5 in 2-3" at 50 yard no problem.

SG Ammo has a good deal on them...Just need to decide if I want full power or reduced recoil version. I have seen erratic grouping with reduced recoil at longer ranges with certain loads....

I get right about 2" @ 50yds with the truballs from a 14" Benelli smoothbore and an RMR red dot. Sometimes a tad more, sometimes a tad less. I'm sure I'd be more accurate with an actual shotgun scope. Although my 18" KSG prefers Brenneki/Aero type slugs, federal TruBall is the slug I stack deep.

If you plan on hunting with TruBall, keep in mind the plastic ball does NOT separate from the slug. It's not attached at all, but I've always found it right there with the slug, even 50yds away.