Gonna set up blind for my grandson to use for pigs. Which choke would work best for #3 buck-shot in my 20 ga.?

It depends on the ammo, gun and choke . You must pattern the load.You want a tight pattern. I would start with a MOD choke .

It's hard to choke down buckshot without blowing the pattern. I would try imp. cyl. and keep ranges short. 25 yds. or so.

i just went through this with an 1100 for my kid to shoot does in the early season youth hunt. i used three inch winchester #3 buck. i shot 5 pattern sheets with each choke tube. started with i/c and ended with full. the improved modified was the tightest out of that gun. there is no easy answer as mete alluded to. it is the relationship of the ammo to the bore diameter and constriction.

I think it is quite well established that in most guns, large shot sizes such as buckshot pattern better in the IC - Mod. In a lot of cases the patterns are very poor through the tighter chokes.

I use a extra full for 3 inch mag OO for yote I found after shooting hundreds of rounds of buck a tighter choke gives some very good pattrens. But the only real way to know is shoot to shoot it.

I wouldn't think buck would make a very good pig load un very close under 20 yards 15 would be better.