Never slugged a bore before; is that done by pushing an oversized lead bullet down the barrel with a wooden dowel and then measuring the diameter of the bullet with a caliper?

I spoke with the seller of the carbine for a good 20 minutes. The rifling is the weakest near the chamber and gets stronger out to the muzzle. I feel pretty good about buying from him, he even stated that if I'm not happy with the carbine he will take it back, and judging by his reputation on that forum I have a feeling he'd stand by that statement. As several people have said, that rifle with the iffy bore is a risk, maybe more risk than I am willing to take. So I'll sleep on it and make my decision tomorrow.

Either way, thank you all very much for your help, can't wait to get a Krag to the range and see why you guys are so obsessed with them  ;D