Question on drilling cartridge.

[sharps4590]

On a pre-WWI, Gebr. Funk drilling the rifle cartridge is marked 172/28 or 26, what might that be? I'm quite ignorant of how that proof mark works.

Thanks!

Vic

[algmule]

Hello
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Peter

[mike ford]

Vic,
This bore (not groove or bullet) diameter is most often found on one of the various rifles chambered for a nominal 8mm cartridge. A chamber cast will likely be necessary, together with "slugging" the barrel, to determine the actual cartridge. However, some hint may be gleaned by checking the rim recess diameter.
Mike

[sharps4590]

Thanks guys! The drilling isn't mine, I was asking for a guy on another web site. It appears it is an 8 X 72R.