The only bore gauge that I know anything about is the Bulley. The one I have only measures 12 and 16. He makes another one for 20 and 28. Mine seems well made a gives repeatable measurements. Bore and choke constriction measurements are easily obtained. I have not measured pit depth but it should do well on ones that are not tiny. He has a you tube demo but I do not have the link. Bob

I have a pair of Skeets which will together will measure from 28 to 10 gauge. I also have Hosford's new $800 gage which will measure with high accuracy from 28 to 10 and with good accuracy, 8 gauge.

The Skeets gages are functional but the Hosford is better. How much? The Hosford is like AH compared to a VH. Both will get the job done...

Mark

If one is looking for a duck or goose gun then the last 6" does matter.