JLN - Its actually a Browning built by Miroku. Jim - I have two Superposed that I would like to open up but they're both RKLT FN guns so not an option. Chuck - The tubes are 3" down the muzzel and the original choke constriction starts 4 1/2" inches down and constricts to .708 in that 1 1/2" (to the beginning of the tubes). As Shotgunjones states, the bore's long choke constriction wasn't addressed by the individual that performed the work to install tubes. I'd like to open the pattern up to IC or SK but the original constriction to .708 that still exists in the bores precludes that option. Brownells has a piloted bore reamer of .725 that would do nicely IF the bores aren't chrome lined.
