Let me guess
Expert shells ?
They are my LAST choice
I have patterned them out of several guns
None shot them well , most patterns were poor to realy bad

No 2 guns pattern the same ammo alike
His gun might have loved that load , while your hated it

Pattern any loads out of your gun
Even 2 of the same brand guns with the same choke will pattern different
Switch chokes and they will still pattern different

John