Rust in barrels.

[His lordship.]

Was at a gun show yesterday and saw what appeared to be a nice black rebuild of the CZ-52 pistol made in 53'.  I already have a year 53' in the parkerized finish, and was about to buy the black one as I think these guns are a good value.

Brought along a cleaning rod with a cotton cloth attached to wipe out any grease inside the barrel for inspection.  Noticed what seemed to be rust in the chamber, and rust residue on the barrel crown, which did not wipe away with my finger.  Looked inside the barrel and it looked like it was very thick with corrosion, ran the cleaning rod through and the cloth came out lightly brown.  Passed on the gun.  

My 2 questions are...can grease become rock hard to look like severe rust, and should I have used a light oil to try to break it up?  Or was it really extreme corrosion from not being cleaned after shooting corrosive ammo through it?  I have never seen a barrel look like that before, I told the seller it was badly rusted, now I wonder if the grease can simulate that over the years? :?

Thanks

[kevin]

I think you were in the right to pass on that one, have seen a few guns packed with cosmoline that for some reason or another caked on, and resembled rust, the differece that i noticed was with caked on greese the grease will sort of flake off and will be lumpy (best way for me to discribe it), and rust will, depend on its severity will usually leave light pits or dark blemishes, and have cleaned blemishes but takes lots of polishing, but all in all good choice.
                                               kevin