I would probably stay in the .695 to .705 range for Pb 4s. I have a .685 Rhino that I use with the Nitro Co. 3 oz. #4s that performs better than any choke I have with that load, but the choke really doesn't shoot anything else very well (Win., Fed., Remington). For the Win. shells (XX or HV) there are three chokes I like for the Pb #4s. The chokes are a Kicks .695, a Tru Glo Strut Stopper by Bansner (old style Strut Stopper), and a Comp-N-Choke XX Full .705. I have a Trulock .695 on the way to try with the Win. shells and a Trulock XFull (.735 I think) to try with the Fed. FC shells. I will report back with the performance of these chokes.