Okay stupid question time.I read once that 8mm mausers had two bore sizes the early one had a smaller bore.If this is true would a yugo M48 have the smaller bore.My local gun shop has a yugo M48 unissued all # match nice smooth bolt action good bore asking $189.00.I can get him down to $150.00 maybe.What do you think?

I think that all the Yugo M48's and 48A's that you're seeing on the market now have the .323 bore like the 98's. These are nice rifles. Pick one up. You'll like it.

That will be a .323 rifle. The .318 bore was made untill 1905 then they switched to the .323 bore and most of the origional .318 rifles were recalled and rebarreled.

The 1888 Commission rifle, Germany's first 8x57, had a .318 groove diameter and an action not as storng as the 1898 Mauser. The 1888s are the reason for American factory 8x57 ammo being loaded to about .30/30 equivalent. In Europe rifles with .318 barrels are called 8x57J and rifles with .323 barrels are 8x57JS. The J stands for infantry and the S stands for the larger diameter spitzer bullet introduced in 1905.
My Yugo 48, in new condition, has a .324 groove diameter and is safe with any factory ammunition. Hope this helps, curmudgeon

curmudgeon is absolutely correct

No, I'm absolutely correct. Curmudgeon just said it first.

Curmudgeon is an extremely smart, and above average as a grade school student. So saying, he is absolutely right.

I will add, not only is factory ammo safe, you can spice these up considerably if you want. Good strong action.

No military Mausers in 8X57mm had the "J" bore since 1905. All after 1905 were "S" bore.

$150 for an unissued M48 is a good price. Like Aquavit said, pick one up, you'll like it!