Measuring choke

[Dean Romig]

I think you will find the "Bore Master" by the Robert Louis Co. to be the most convenient to carry around gun shows and exhibitor's tents. having a max. depth of 6" it will measure the chokes and chambers of ALL popular gauges.

[Double Lab]

I have the Bore Master and find it difficult to get repeatable readings with it's only 2 points of contact as opposed to my other dial gauges having 3 points of contact. It is handy for a quick assessment though.

[Bill Murphy]

There is a lot more to a $10,000 shotgun barrel than 6 inches at each end.