I'm not so sure it'd be a very good idea.

While the graphite would lubricate the parts, it would do nothing to repel moisture and prevent corrosion. Also, if the graphite ever got wet it'd turn into a crusty mess. Not to mention that it'd be likely that every time you handled the gun would get graphite dust all over your hands, the gun, your clothes, etc...

If you want a lube that, when applied correctly, leaves both a semi-dry lubricant (teflon) as well as being an outstanding rust preventing preservative, then get yourself a bottle of "Break-Free CLP". It's the same stuff that is issued and used my the U.S. military and it is very good stuff. While wet it acts as a mild solvent for cleaning, then after cleaning a very light coat is applied to all parts you want to lube and/or preserve. After a little time all that's left is a fairly dry feeling coating. The military had CLP developed to provide Marines (and soldiers) in the field with a means to perform all three vital weapon maintenence functions (cleaning, lubricating, and preserving) in one bottle, thereby reducing the amount of crap the Marine has to carry. The other requirement was that the lube/preservative could be applied light enough that the weapons wouldn't attract excess dust and dirt like conventional gun oils.

Mike