It's not a dial gauge, Dave.

Just a set of el-cheapo telescoping gauges that you lock, and then measure with a standard micrometer.

You gotta get them out of the bore to measure.

They work 'most' of the time. A recess choke would be a problem, and possibly require a dial gauge.

I can't justify a dial gauge in 410.

http://www.harborfreight.com/6-piece-telescoping-gauge-set-5649.html


"The price of good shotgunnery is constant practice" - Fred Kimble