I will second the bore light suggestion. Make sure that the bore is shiny with no crud, rust, or pits. Make sure that the crown isn't dinged up. Make sure that the rifling is square and not rounded over.

Cycle the action and feel for any binding, rough spots, etc... If you can get some dummy rounds take them with you and feed them onto the magazine tube and cycle a full mag through the gun a few times.

Cycle the action and look to make sure that the hammer rotates past the point where it engages the sear. You want the hammer to over rotate and then rotate back foward to engage the sear when you work the lever. This ensures that the hammer engages the sear every time rather than missing it and having the hammer follow the bolt down.

With the hammer fully cocked push the hammer foward to make sure that the sear and hammer engagements are not worn our and/ or no one has messed with the trigger in a bad way. Also do this from the half cock (safety) position.

Look for cracks in the stock at the tang (part of metal that sticks into the wood).

Make sure that the screw slots are nice and crisp with good edges. If the owner can't unscrew a screw with out buggering it up then you may not want the gun if that person has been inside it.

If you are looking for one that is in original condition and not refinished then also look to make sure that the screw holes are not washed out and that all of the lettering on the barrel is crisp with sharp edges. By washed out I mean one side will be sharp and the other side will be rounded over. This is caused from polishing wheels getting into the holes and removing metal from one side of a hole/ letter. Either way I wouldn't want a gun with washed out holes as it really makes a gun look like crap.


Good luck.

Oh yeah, if they won't let you examine the firearm in detail then don't buy it. I don't mean take it completely apart but a good reasonable going over shouldn't be a problem for a person selling a firearm if they aren't trying to hide something.