I would loan out my 2 old single shot shotguns. They have been dragged through the woods for 60+ years and it would be hard to make them look any worse than they already do.
I "might" loan out my rifles to very special and trusted friends but it would be hard. They both still look and perform like new.
I won't loan out my handguns. There is just to much that could happen to someone if they were not handled properly.