doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Skeets bore gauge

For measuring bores I just use a Starrett telescoping gauge set equipped with a 12" handle & a micrometer. Works great & is comparatively inexpensive. In my case, I already had them from my machine shop days. For wall thickness, one needs specialized equipment as it cannot be counted on for the OD & ID to be concentric.

I took delivery of the 16-12 gauge bore skeets bore gauge and was disappointed that it wouldn't fit into the left barrel of a 16 ga. Robust. The diameter of the brass structure which contains the spring loaded ball bearings is .623 and according to my calipers, the full choked muzzle diameter of the left barrel is .615. Bear this in mind if you intend to measure European barrels with the 16/12 Skeets instrument. Gil

I have the Skeet's 12/16 and the full Stan Baker set for this very reason. The Stan Baker 12/16 head will not measure bores on the larger diameter side of standard 16 bore. Neither set is perfect but between both of them and a set of plug gauges I can pretty much measure anything I need to.

I'm almost afraid to buy one of these gadgets. My safe full of old worn out guns might have some real surprises in the barrel thickness department...Geo

Geo, you'll know you have big trouble if the ID is larger than the OD. Gil

I once owned a Boss gun that fit that description...Geo

Galazan's $500 gauge will measure all gauges up to ten except for .410, and according to my measurements, will measure eights with some minor machine work. I use a "small hole gauge" and a zero to one micrometer to measure .410s, a cheap alternative to a bore gauge and takes up much less room.

My telescoping gage set I mentioned has a small head that goes down to .375", small enough to measure even the choke on a .410. 8-Bore's small hole gage does the same thing, both are fit to the bore, extracted & measured with a micrometer. Unless you are in business & need to measure a lot of bores in a short time, you don't need a lot of expensive equipment to measure an occasional bore. You are only measuring a diameter here, concentricity plays no part as it does in measuring wall thickness.

I have and use a set of Starrett telescoping gages and there is a right and wrong way to use them. Let's see who knows the correct way to use them.

Put the gage in the bore with the handle off-center. Snug up the screw & pull the contacts over-center "One Time". Finish tightening the screw making certain nothing moves remove gage & measure with a micrometer.

That's how I was taught by old-time machinists who had likely worn out a few sets of them. This has always worked for me & I have checked myself against precision dial bore gages & been extremely consistent with both devices.