Building Confidence

Riverpigusmc · #1 10-24-2020, 11:33 AM

A cheap digital micrometer is your friend..then you can mic pins and see the variations in what pins you have

FfNJGTFO · #2 10-24-2020, 11:48 AM

Quote:

Originally Posted by Riverpigusmc

A cheap digital micrometer is your friend..then you can mic pins and see the variations in what pins you have

Excellent,

! I will get one. I hope I can also measure the holes the pins are supposed to fit in so I can gauge what size pins I need.

Thanks!

DrHenley · #3 10-24-2020, 12:43 PM

Quote:

Originally Posted by FfNJGTFO

Excellent,

! I will get one. I hope I can also measure the holes the pins are supposed to fit in so I can gauge what size pins I need.

Thanks!

Normal micrometers only measure outside diameter, not inside like calipers can. Inside micrometers are for large holes (>1")

To measure a small hole, you'll need a small hole gauge, which you expand until it fits the hole, and then measure it with the micrometer.

https://www.amazon.com/Starrett-829B.../dp/B0006J4Q96

FfNJGTFO · #4 10-24-2020, 01:13 PM

Quote:

Originally Posted by DrHenley

Normal micrometers only measure outside diameter, not inside like calipers can. Inside micrometers are for large holes (>1")

To measure a small hole, you'll need a small hole gauge, which you expand until it fits the hole, and then measure it with the micrometer.

https://www.amazon.com/Starrett-829B.../dp/B0006J4Q96

Thanks much! I figured there was a trick behind it.

Gatorade · #5 10-24-2020, 03:31 PM

Sometimes you can check the hole size with a drill bit.

FfNJGTFO · #6 10-24-2020, 03:46 PM

Quote:

Originally Posted by Gatorade

Sometimes you can check the hole size with a drill bit.

Or a Roll pin punch. I have one in the gas port now keeping things aligned, if not totally fastened, while I order more pins.

DrHenley · #7 10-24-2020, 08:43 PM

Quote:

Originally Posted by Gatorade

Sometimes you can check the hole size with a drill bit.

I've done that, and I have a 115 piece drill bit set. But if it's slightly loose the next size up won't fit, and if it's slightly too tight then then the next size down will be way too loose.

Unless it fits perfectly, it just gets you a ballpark.

I had problems replacing a firing pin on a revolver. The firing pin shaft was 1/4" exactly, but the hole was too tight for it to go in and I couldn't figure out what was going on. The drill bits didn't help and I had to take it to a gunsmith and let him deal with it. Turns out the hole was peened ever so slightly making it just barely smaller than the firing pin shaft. I mean it was sooooooo close but the firing pin just would not go in.