New Russian Calibre and Rifle

[JohnV]

You don't need to obtain specialized tooling to rifle a barrel to any bore /grove size you want . The button can be produced on any decent lathe , milling and honing machines . Same with projectile manufacturing dies . Russian can make a .243 barrel anytime they want .

[Border_Bloke]

I'm sure they're talking bore diameter (or calibre), not bullet diameter.

Yeah you're probably right I didn't think of that.

The 7.62x54R, 303 & 30-06 are all named for their bore diameter.
The 7.62x54R & 30-06 are both 0.300" / 7.62mm bore diameter, the difference in bullet diameter is because of rifling depth.

[bigrich]

I'm sure they're talking bore diameter (or calibre), not bullet diameter.

Yeah you're probably right I didn't think of that.

The 7.62x54R, 303 & 30-06 are all named for their bore diameter.
The 7.62x54R & 30-06 are both 0.300" / 7.62mm bore diameter, the difference in bullet diameter is because of rifling depth.

i could be wrong , but i think the 7.62x54R russian rounds bore is closer to 303 british than the 30-06 . it's measured differently i think . top of the lands instead of the bottom . i think .......

[bladeracer]

I'm sure they're talking bore diameter (or calibre), not bullet diameter.

Yeah you're probably right I didn't think of that.

The 7.62x54R, 303 & 30-06 are all named for their bore diameter.
The 7.62x54R & 30-06 are both 0.300" / 7.62mm bore diameter, the difference in bullet diameter is because of rifling depth.

i could be wrong , but i think the 7.62x54R russian rounds bore is closer to 303 british than the 30-06 . it's measured differently i think . top of the lands instead of the bottom . i think .......

No, as far as I understand the 7.62x54R is a .300" (or "three line") bore, it just has deeper rifling than the US used, which I think was mainly done to expand tolerances of manufacture. The .303 I think was always a .303" bore with .004" rifling - I have no idea why they didn't use .300" and .308" though.

Bore is always measured to the lands as it's the hole you drill or bore before you cut the rifling into it.