good morning. I've been to some forums about mauser k98k. But I've no answers about this question. I'm going to buy a k98k and I've found in internet that some business listings say that the rifle use the 7.92x57 "JS" and some others the 7.92x57 "JRS". I've read the differences between these two kind of ammos...but...depends on what??? thank you friends! Wanna kill these ads? We can help!