I was given an old Mossberg .22WMR in rough shape. There was some rust on the barrel that I hit with some fine steel wool and got most of it. Any idea on how to get rid of the pitted stuff or how to rid the inside barrel of any rust that may be in there (besides a good cleaning)? How do I know if it will be safe to fire? When I look down the barrel it doesn't look too bad. Probably been 2 yrs since last fired. Probably not cleaned afterwards. Never had to deal with an abused rifle before.
Also looks like the stock is very slightly warped to one side and is putting just a bit of pressure on the barrel. Would the best approach be to just take off a tiny bit of the wood where the barrel seats?

Is it worth it to you to put forth the time, effort and $ to retore it? I would just scrub the barrel real well, not even worry about pitting as you can't do anything about it, feel free to take wood off the stock if you believe it is binding or putting pressure and then invite a buddy out to the range with you, and have him be the first to take a shot from the hip!

If there is a question about the safety of shooting the gun, I'd suggest taking it to a smith to inspect.

Clean the barrel out the best you can until it looks good. Clean the bolt and action. Lash it to a tree, tie a string around the trigger, take cover, and fire it. If it's still there and the barrel looks good, disassemble it, do what you wish to the stock, paint the barrel and action flat black, and keep it for a truck gun. (The aforementioned comes from many previous experiences....)

Good advice

I think I may try a paint job on at least the barrel. I saw some guys that did home made camo paintjobs in another post and they looked pretty good. May as well start with black. The wood on this one actually cleaned up very nice. The grain on the older guns is so much nicer. The barrel is looking halfway decent and the action slides nicely now.

Now to find some string and a nice wide tree....