Hello Caribou. You are giving information which doesn't make any sense whatsoever. We will need to see pictures of every part of your "carbine" in order to help you out. I'm not even sure you are describing a Krag. It sounds like there has been significant damage done to or alterations made on your firearm. No Krags were ever made at Springfield Armory without a serial number. Sometimes they are sanded off or partly removed with drilling and tapping the receiver for a scope mount.

I'm really curious what you have but please post pictures.

Thanks!