Useful pin gauge sizes for revolvers?

[Elric]

This is considering the use of pin gauges in determining cylinder mouths and maybe throats in revolvers. Since a pin gauge has to be used in the real world [non-perfect holes], it seems they are a guide.

A hole could be "jugged", ovoid, or stepped. Pin gauges will fit through the smallest straight cylindrical passage which might not be the actual width.

Bullets vary in diameter, design [front band existence, width, circumference, PB, BB, etc], hardness. Throats vary. Bore and groove vary.

In the end, the pin gauges suggest the useful diameter. Experimentation will prove the best size, perhaps the op will see the need for reaming the chambers or throat.

For a caliber, what pin sizes are useful? Unfortunately, some historical cartridges [.45 Colt?] have chamber mouths, throats, and bore dimensions that just do not play well together.

Example pin gauge size for caliber [SWAG]:
.357 Mag: .355 - .360 [Brad]
.41 Mag: .408 - .411
.44 Mag/Spc: .428-.434 [Brad]
.45 ACP: .451 - .453
.45 Colt: .448 - .457 [Brad]

The more information, the better. If there is a list somewhere for this diameter range, where? I'll go get it.

 

[Brad]

For 357/38 I would say .355 to .360
44 mag/special .428-.434
45 Colt .448-.457

When I went to look at my Model 25 45 a Colt I had a .451, .452, .453, and .454 pin in my pocket. I had already decided that if it took the .454 pin it was a no go. Luckily the .454 didn’t fit but the .453 did. Made a sizer for .453 and never looked back.

I look back on things and wonder how I ever got by without them?

 

[Rockydoc]

If the purpose of your measuring revolver cylinder throats is to find the correct diameter bullet that will work best, you don't even need pin gauges. You just drop the bullet into the cylinder from the back, some bullets will fall through from their own weight, some won't go through without a lot of hard pushing. You don't want either of those. You want bullets that require a gentle nudge with a pencil or other dowel. If your cylinder throats are not the same diameter and will need reaming or polishing you make all of the throats the diameter of the largest one. This can still be determined without pin gauges by dropping bullets of different diameters to determine the largest, then mic that bullet.

 

[fiver]

but then you gotta have sizers in that diameter.
so 40 bucks for a size die or 50 cents for a gauge pin?

 

[CZ93X62]

I invested ~$200 in my gauge pin sets 12-15 years ago. I have saved several times that much money and incalculable aggravation by NOT buying out-of-spec firearms, thanks to the findings of the Firearm Polygraphs--my pin gauges. I've had a couple sellers at gun shows refuse to let me use the gauges on their wares (S&W 44 Magnum revolvers), so I just walk away. THAT is what I mean by "Polygraph"--you can learn as much via refusal as you can from test results, at least what direction to take.

 

[Rockydoc]

but then you gotta have sizers in that diameter.
so 40 bucks for a size die or 50 cents for a gauge pin?

I have pin gauges and recommend them. But, just saying, you can adjust the size of a test bullet in many ways, PC. bump, change alloy, etc., if you don't want to spend $ on a set of gauges just now.
Just sayin'.
After you have determined the size bullet needed in the afore mentioned test, you can then buy the sizer that you need.

 

[Brad]

Just shove a slightly oversized bullet thru the throats and measure with a micrometer. Works fine. Just takes 6 bullets and is far easier with the cylinder removed from the gun. Damned near impossible to use at a gun show or store.

Pin gauges do cost but are reusable and quite portable.

Having a few machine tools they also do double, or quadruple duty.