[Copernicus]

Well, my book says american 30 calibers are either .308”, .3085”, or .309”. The british 303 is .312”

I will cheerfully read your book if you will supply the title and author.

Best regards,

[mamelukesabre]

I’ll give you several.

A catalog for speer rifle bullets...any one will do

A catalog for hornaday rifle bullets...any one will do

A book with exact dimension and drawings of rifle cartriges...title: “Modern Sporting Rifle Cartridges”, by Wayne Van Zwoll.

The british, russian, and japanese 30 calibers are roughly equivalent(.311 or .312) and can be interchanged with eachother, but NOT with the american 30 calibers, which are usually .308.

Additionally, you can look up these calibers on wikipedia and see the case, bullet, and cartridge dimensions there.

30-06 springfield
308 winchester
7.62 NATO
30-30 winchester
30 carbine
300 savage
30-40 krag
307 winchester
300 winchester magnum
300 weatherby magnum

Then compare those bullet diameters to these:

7.62x54R
7.62x39
303 british
7.7 jap(aka 7.7x58 arisaka)