Using pin gauges to measure barrel diameter?

I purchased some Cerrosafe to slug some pistol barrels but realized having a set of quality pin gauges that might also do the job.  Seems like it would be just as accurate in determining barrel diameter.  Any downside to this idea?

Greetings,

Pins will give you an approximate Bore Diameter. Unless you buy a set of Deltronic Tenth pin set.

When you buy pins, read up on the tolerance specifications.

To measure the Groove diameter, the Brown and Sharpe Intrimiks work well providing you have a six groove barrel. Mitutoyo also have a similar offering.

CerroSafe works well as you can melt it down and try again should you not like the resulting casting. Downside is that it grows upon cooling.

ReproRubber is a two part casting medium, comes in paste and liquid, and it produces a fairly close casting, dimensionally.

Cheers,

Dave

If you looking to measure the root diameter of the barrel ( diameter minus the dept of the rifling) Pin gauges will work. They are in .001". Chinese set .061 to .250" is about $50 but .251 to .500" will get a little costly. They come in Plus and minus sets. In the cheaper ZZ set the tolerance is .00020", the plus set the pins can be .00020" larger and minuse set .00020 smaller. The tolerance decreases as the grade gets better Z tolerance is .00010" and get smaller but the price increases rapidly! However you can by the pins individually, each they are not very expensive depending on the grade. Tenths pin set get kinda expensive in the you have 10 pins for every .001"
 I don't think Intermik will work well. it will depend on the type of rifling and rate of twist. I have a few of them and they get kinda expensive!!! Cheaper SPI set of 3 to measure .275" to .500" is over $1000.00
 Bismuth alloys will melt in boiling water so you can cast your bore diameter.