Measuring Devices

[ryan richards]

A lot has been said about the need for accurate measurements regarding barrel diameters, cylinders throats, and a host of others dimensions necessary to optimize our beloved pistols and revolvers.

How accurate is necessary?

What measuring tools are recommended to accomplished this accuracy?

Let's here it from those who know.

[OeldeWolf]

There are a LOT of measuring devices available. Most people on here seem to do quite well with a good set of calipers and a good 1 inch micrometer. Next nicest item would probably be a set of pin gauges.

Just my thoughts.

[mtgrs737]

I use pin gages as it takes the err out of cylinder throat measuring. You will still need a good caliper or mic for the measuring the bore slug, one that reads to .0001" would be nice.

[theperfessor]

I have found that a good set of expanding leaf-type small hole gauges, available from Enco, MSC, and many other sources, along with a good outside micrometer will enable you to measure cylinder throats very easily and with practice very accurately. These are transfer-type tools, as they transfer the dimension you're checking to another tool. I use a cheap set since all the required accuracy is in the micrometer.

Although I have a good set of inside mikes and other precision measurement tools when I'm fitting things together I use small hole gauges and telescoping gauges so that I can use the same mike to read both inside and outside measurements with the same tool. It eliminates any slight calibration errors that come from using two mikes.

Pin gauges are also good but more expensive and will only tell you if something is larger or smaller than the gauge being used, they will not tell you exact size of hole. But they're good enough for most things gun related.

Just my thoughts.

[Willbird]

In my line of work I have used quite a few telescope gauges and small hole gauges, the trick is learning the proper "feel" to get the right measurement, this can really only develop if you have another way to verify what your getting as a reading. I really hate cheap telescope gauges and small hole gauges, the Starrett ones are worth looking for at pawn shops and on Ebone.

On micrometers there are indeed many imports avail now that will measure to .0001 and folks who actually calibrate tools say they are a viable alternative to having higher quality tools recalibrated every 2 years or whatever is required, they sell the used ones on Ebone and just buy new ones at some interval.

To properly use pin gauges you need a selection of + and - in whole and half thousance. If a .250+ pin will enter a hole and a .2505- pin will not we know the hole is between .250 and .2503....thats nailing a hole size down pretty darn close ;-)



Bill