Have a milsurp K98 that has a catch when you lower the bolt handle. You don't notice it when cycling the action quickly but when the bolt is pushed forward slowly and then pushed down (like when decocking) it feels like it is hanging up. A bit of force overcomes the hang up but is there some polishing that it needs?

First isolate the problem. Cock the bolt and move the safety to 12 o'clock. Remove bolt, depress bolt sleeve lock plunger, unscrew fire control and set aside. Insert bolt back in action and repeat your test. If it happens again then the problem could be with the safety lug, lug setback, lug recess machining, boltface projection clearance or bolt body clearance. If not, then it could be tight bolt sleeve threads or a rough cocking cam. Disassemble fire control and test bolt sleeve fit to bolt body. Observe cocking cam for rough machining or galling.

Do you have a K98, or a 98k? Big difference in the rifles; bolts are the same; as Bobster said, could be lots of things. Coat the bolt with layout dye and see where it rubs. Or coat it inside and outside with fine polishing compound and work the bolt 50 times. Clean it and the roughness will be gone. Maybe.
I have done so many Mausers I can tell by the feel where the hitches are. Like the pinball wizard; young guys will have no clue what that is.

It's a WWII Czech Mauser my dad picked up during the war. I'll tear down the bolt and determine if that makes a difference.

Ah, then it is neither a K98, nor a 98k; it is a VZ24. Same bolt though.

The "catch" is simply the sear on the cocking piece moving forward to engage the trigger sear as you are slowly lowering the bolt handle. I have an original Oberndorf that has had the cocking piece altered to hasten lock time that has the same catch. To check that this is the cause of the " catch" simply pull the trigger and hold it back while lowering the bolt handle and you will find no catch.

Pull the shroud lock out of the bolt shroud then see it still does it.
Don