I have a model 70 that I bought back in 2005. I fired about 10 rounds through it, cleaned it oiled and stored it under the bed in a hard case. I would take it out every month or so and check for rust and re-oil it. So I took it out for the first time since 05 last week fired about another 10 rounds through it and cleaned it. While cleaning I noticed a little bit of light rust near the muzzle. So I gave it a good bronze brushing, no luck. So I bought a brush and some super cleaning rust removing crap they had on the shelf at the local shop and gave that a try. No luck. I am afraid to get to aggressive as I dont want to damage the barrel. Any suggestions? I should also mention that I plugged the end of the barrel with paper towel and put some oil down the barrel and let it soak for 2 days. Still no luck. I am about to take it in to a shop for some professional cleaning but thought I might try here first.
Thanks in advance for the help.

4/0 steel wool + rem oil

Get a tube of Flitz metal polish. It will clean it and protect from more rust. Can use it in the bore, too.

If you soak the part in coke a cola it will remove the rust. I do not know how it will affect the bluing so you might want to try it on a some thing else first.
Naval Jelly, not from you belly button, will also remove rust with out sanding but again its acid so it could affect the bluing.
I herd molases will remove rust also.

There is another method of electrolysis that will remove only the rust and could possibly not hurt the bluing.

+1 for Flitz

Thanks guys for the advice. I have also had a few friends tell me to shoot it out. Oil the bore very well and shot a lot of round through it. Ever hear of that working?

I would not shoot it out it could do way more damage in the bore. Instead of small pits from the rust you will now have pits and deep scratches .Actually i did not read it was in the bore I would tape everyting off good and use the naval jelly , sold at the auto parts store, and brass brush. Let it sit for about 20-30 minutes ,wet, and brush and clean. I would imagine that would be all you need. The naval jelly cost 5 dollars and will dissolve only the rust. Be careful when you brush you dont want to run the brush back and forth in the bore only one way.

Flitz is a metal polish and it great but I would not use it here.

Is the rust in the lands or the grooves?
What type of ammo are you shooting?
If it is just surface rust it will shoot out.
You may do more damage by trying to remove it mechanically or chemically.

Since it looks like you are Houston I wouldn't store it with a paper towel or rag with it as they will trap some of the moisture in the air and keep causing problems like you have.

If you aren't going to shoot it often I would spray it down with breakfree or any type of oil that has the grease in it for longer storage.

Hope this helps and just my $.02 which may not have helped what so ever LOL