Yes, they are a so called mini mauser style action they are very popular with some people. CZ and Remington both have rifles with mini mauser actions but they are sightly different from each other. What caliber is the rifle you are looking at?
Edit: I assumed it was a mini mauser action. Oops!
The commerical mauser actions imported by Interarms are supposed to be of good quality from what I've heard. If its a fair price you'll probably get a good rifle.
I've had several. they are very well built actions. I have one in 338 win mag that i'm working up loads for.
I built it 33 years ago and now just getting around to using it.
I've had some and they were ok. I think the actions are basically good (hard to go wrong with a big ring 98) and if you find a good shooter you're set.
IIRC, the majority of Mark X's imported by Interarms were from Yugoslavia and the barrels were vanadium steel.
More recently I think the same basic rifle was or may be imported today under the Charles Daly name.
In 1983 I built my wife a .375 H&H using an Interarms Mark X action and it turned out great. We had planned on getting an asignment to Alaska and do some bear hunting but it never happened. We ended up in Oklahoma when we retired. She still likes her .375 H&H and being built so it fits her well that she can stand the recoil without any problem. I've always made sure she shot it standing up though. The action is a well build Mauser that is very smooth and well built.
Mark X is a great commercial Mauser action. I have had several over the years, including 30-06,300, 338, 375 and 416. They are great actions with plenty of strength.