Now moving right along, Sorry that this is a very long diatribe!
Let us move along to the action of the rifle.
Does it operate smoothly?
This video will give an idea as to how it should go as concerning smoothness. The first 30 seconds is all you need to see.
If yes then you are good to go!
How does the metal of the gun look like?
Does it look uniformly clean w/o any rust, pits, stains, scars, bulges, cracks or stuff like that?
How does the inside of the barrel look like?
It should look like this
How does the trigger feel?
Ask if you can dry fire it.
If the trigger have a reasonable resistance to pressure and then breaks clean. (You will feel it when you do it.)
If not – You can still think about getting it. Since you can usually replace the trigger with an aftermarket one. Which will cost around another $100.
Move on the next section