I am not 100% positive, but isn't a Kar 98b built on a small ring/large thread action like the Kar 98a? I thought the actions were the same but not the configuration?
If it is the small ring/large thread action it is not suitable for much more than a 257 Roberts although I have owned and fired many Kar 98a in 8x57 with full power loads and a 30-06 or 2
ETA: A Kar 98B is a standard Large Ring 98 action of WWI vintage. Most are just fine to build anything on. The really safe 98's with no worries are 1935-1943.
Last edited by sbrmike; 01/24/17.
