Thanks for your inputs. I oz, I searched the other forum and found lots of opinions and experiences. Thanks. I talked with a representative for Muller Chokes on the phone regarding the difference in my bore diameter (.738", both barrels) versus the factory adverticed .742" bore. Their opinion is that this difference in bore diameter will not effect (or change) use of their chokes. Perhaps so, since theirs overlap the standard chokes.
My gun is a Browing Citori 625 Sporting O/U, 12 ga.
I'll make one interesting point: When I purchased my gun, it came with five Invector Plus, Diamond Grade, extended choke tubes. The exit diameter of these chokes all matched the .738" bore diameter to give the proper constriction. Exit diameters are .733 (skeet), .728" (I-cyl), .718" (mod), .713" (I-mod) and .703" (full). These choked were matched to the bore diameter from Browning. I have since purchased a cylinder choke and it measured .742" which matches the advertised bore diameter and not mine. This was the premise for my question to Muller chokes.