I was fooling around at the bench the other day and decided to try measuring the choke on some shotguns to compare with what they were marked. Most came out pretty close to what they were stamped, but a 12 ga. 870 marked full measured .709 (modified).
To measure, I was using the micrometer I use in reloading rifle rounds which has a 0.6 inch reach for the inside diameter measuring function. Is this enough reach to catch the choke? Or, could the choke be further back in the bore than I can reach with this micrometer?
