7.62x54R and .303 British Headspace Dimensions?

[MissouriCrowinMass]

I have two Okie Field Gages for .303 British and 7.62x54R. I forgot which is which?

Does anyone know the No-Go and Field Dimensions for these two cartridges?

I'm getting about .075" on one and .078" on the other as measured by my micrometer.

Thanks

 

[gb6491]

I have an Okie 7.62x54R field gauge: measures .075"
Regards,
Greg

 

[rcmodel]

To further add to the confusion, SAAMI case rim spec is .064" for both cartridges.

Hatchers Notebook indicates:
7.62x54R = Rim: = .064" - Headspace = .064" - .068".
.303 British = Rim: = .063" - Headspace = .064" - .067".

Could it be you have a "Field" and a "No Go" guage that works in both calibers?

rc

 

[MissouriCrowinMass]

Unfortunately, MissouriCrowinMass has a few grains short of a Minimum Load memory wise and equally bad record keeping.

I thought I bought a .303 British and 7.62x54R Field Gage from Okie........they both have "3 dimples" which I think is the Field Gage indicator?

One is .535 in diameter.

The other is .564 in diameter.

Both are a whisker within .075" in thickness.

It ain't easy being me.

 

[rcmodel]

One is .535 in diameter.
The other is .564 in diameter.

Well, SAAMI spec case rim diameter is:
.303 Brit = .540".
7.62x54R = .570".

So that ought to sort out which one is which.

rc