I tried various loads in my 1892 Army DA with HBWC bullets, and various seating depths. I can say that with Bullseye and Titegroup, exact seating depth makes a REALLY big difference in the power of the load. So I would say that if you're going to use LC cases, and seat the bullets flush, better start at the bottom of the recommended charge weights. I tried everything from seated flush in LC cases, to .38spl cases, and seated out as long as the cylinder would allow. Seemed like nothing I tried got the skirt to fully engage the rifling, though. You might have better luck with your converted navy, though, since I think they have deeper rifling grooves.
Also, if your cylinder is bored straight through, it should readily accept standard .38spl wadcutter ammo.