Dial caliper and micrometer?

[spurgon]

Which tool does which job best in regard to casting and reloading? The micrometer that I have is a simple 0"-1" type. I'm going to slug my firs barrel soon , for instance. What would be the difference in results using either tool?

spurgon

[Johnw...ski]

Which tool does which job best in regard to casting and reloading? The micrometer that I have is a simple 0"-1" type. I'm going to slug my firs barrel soon , for instance. What would be the difference in results using either tool?

spurgon

The micrometer is fine and a little more precise even if it doesn't read to .0001.
However a good dial or digital caliper is also very accurate and can be read usually to .0005, also, it has a much greater range normally 0 to about 6 inches.
You could measure the overall length of loaded ammo and should also be able to measure the rifling groove in your barrel slug. If you are very dexterous you might be able to measure the rifling grooves in the slug with a micrometer by measureing over dowel pins resting in the groove. So if you had .0625 (1-16")
dowels resting in the rifling, you would subtract the dia. of the 2 dowels (.125) from the total measurement to get the groove dia. It would be much easier to use a caliper.
Hope this helps.

John

[JSnover]

What would be the difference in results using either tool?

spurgon

That will depend on you developing the right feel for each one. Both will measure undersize if you're a little heavy-handed. Be gentle. Practice with a sample piece of a known size, like a gage pin or block. You don't need to buy a complete set to refine your measuring technique.

[VTDW]

Good stuff above. I am too cheap to purchase a good Micrometer :mrgreen: and the Dial Caliper serves my needs for both casting and reloading. I do have a 6" Starrett Micrometer but only God knows where or why I got it or even have it. Must have been in a past life.

Dave

[XBT]

I have both and find that the dial caliper is much more useful.

[NVcurmudgeon]

If i had to choose one, it would be the dial caliper because one needs to measure case and cartridge lengths often. Also the sharp ends of the caliper blades can reach into grooves on a slug and give you some idea of land height. OTOH, I use the .0001" mike for groove and throat diameter on slugs and it is indispensable for case expansion measurements.

[HORNET]

Actually, it's not that expensive to get both. I got a set of digital calipers at Tractor Supply for about $15 and a tenth-reading Chinese mic at MSC for $10. Those are the ones that I use at work in case they grow legs :???:.
You really need a mic for checking bore slugs due to the accuracy limitations of calipers. The range of calipers works real good for case length, loaded length, etc.