i've been happy with the bore gauge i bought from gary bulley in victor, montana (dba - centerfire ranch)....reasonably priced, and he can build with up to 18" shaft....i got a 16" version, which allows measuring up to 32" barrels. the indicator has sufficient travel to measure 16 ga, 12 ga, and bore measurements of 10 ga....but limits out at .800 so 10 ga chambers (and oversized 12 ga chambers are out of reach).
careful use of a bore gauge will give pretty good idea regarding chamber lengths, if forcing cones have been "improved", length and constriction of chokes....which is a good deal of information about a barrel set. it's my belief that most of us can spot a reblacking job by the texture, washed out lettering, not matching the general condition of the gun, etc....that has been my general approach with the lower priced guns that i can afford....hasn't bitten me (yet).
i also have "lowest common denominator" wall thickness gauge - but have been frustrated by attempts to master it's use....i have increasing fine motor skills problems and cannot control the gauge well enough to trust my results. i commonly bring my bore gauge when i walk a gunshow....but only get out the manson's when i want to test my blood pressure....
best regards,
tom
