Several years ago, I had Gary Bulley make two bore gauges for me; the 18" versions that would cover pretty much everything from 10 ga. to 28 ga. bores. He put them into a hinged wooden storage case for, what I thought was a reasonable price. I've been very pleased with them. Regarding the dealers general apathy about barrel dimensions, I think many of them buy a pig in a poke as it were, concentrating more on grade, wood, condition, and engraving than on the basic mechanics of a gun. I would lay awake at night worrying if I were in their place. Some plead ignorance of the barrel dimensions due to effect on sales, and some are just plain ignorant about it. Sandlapper