How Low Can You Go?

So I got a new Gen 4 Vulcan SS, and the gun shoots lights out in the 890’s with JSB 25’s…..but it’s way overkill for shooting squirrels in the neighborhood.

How low have you tuned your gun via HST only, and still maintained excellent accuracy out to say, 30 yards? Also, I know going to polymags or or the H&N hunters will greatly reduce how far the pellet goes after passing through.

Any input is greatly appreciated.