I was mentioning this to a good friend of mine, and he just gifted me this nifty little device. Made in Germany, and finished with all the precision you'd expect from those folks; it feels like a fine engineering instrument (which I guess it is). He doesn't remember where he got it some years ago; possibly Browell's. Pulling the knurled handle releases the three spring-loaded ball bearings which then expand to fill the bore. Pull it back to the point of greatest constriction, read the gauge. Viola! While it won't give me decimals it will definitely fill the need I have at the moment. I may still buy a gauge at some point. Or maybe not.
