Did I read that right?? your friend says that the gun has rust inside?
a) what did you see when you looked inside?
2) where is the rust?
43) How do you take care of your gun? products etc.
69) all unprotected metal rusts. period.
98) clean and protect it, properly
Its been about 4 weeks since I shot last. After shooting I do a basic field strip, clean it, dry it, apply armadillo and last time applied liquid teflon to all parts. I store the gun in my garage, unheated, I just looked at it, not a spot of rust anywhere.
Maybe you should try a different product when cleaning your gun or a different method of cleaning it. not a question, just a statement.
If all guns didn't rust, then the stores would not sell the electric heating rods, dry silica to absorb moisture, etc..
Depending on how you respond will determine if you are trying to cause trouble having come over from another forum or truly concerned.
Let us know more details, many friendly knowledgable people here who can help with product and method suggestions.