Well just got in from shooting the Trulock .581.With the Fed HW #7's had 156 and 148 in 10" circle.Shot another Hevi-13 #7 and had 168 in the circle.I was surprised by how close the different shells shot number wise.I would have expected the Fed to out shoot the Hevi but this was not the case.One thing to note is the Fed had a more recoil then the Hevi.This was somewhat expected due the higher velocity and payload.All things considered I'll probably go with the Hevi-13 due to price and the fact they shoot as well if not better in my gun.We have a .575 Carlsons Extended Non-ported choke on order for the Benelli should get it later this week,I'll try to give a report on it as soon as we get it shot.From what we've found so far these shells both brands seem to shoot well thru a open or tight choke.IMO this is good news for the guy who doesn't want to spend a bunch of money on chokes, either of these shells should give satisfactory results in a standard full choked barrel.I would venture that they would still put over the magic 100 pellets in a 10" circle with a gun so choked.Hope this helps someone.Thanks Todd