Opinions on this gun solicited...I have wanted a German 98 Mauser Classic Stalking Rifle for quite some time! I just bought this on Gunbroker and I have a few question? Is this most likely a 8x57J or S ? Isn't there a difference in the bullet diameter? Also what is the commercial American ammo? J or S ? Are both loaded in Europe? Are both available in America...Where? TIA. Jerry