I have an unloved .22cal Condor sitting in the cabinet that doesn't get used and was thinking that it might be able to be turned into a dedicated slug gun. What would my barrel options be for 25-30gr slugs?
They will shoot slugs fine. You just need to figure out how much choke is in the barrel and then buy the appropriate sized slugs for the choke or size them yourself. They have plenty of power to fling the heavier slugs pretty damn fast.
Yes, what you want is the diameter of the grooves at the tightest part of the choke. Start with that measurement and go with that size slug and one under and over. That should give you a good idea of what your gun is going to like.