Unless I'm mistaken and it is nickel plated, or something like that, you can remove the grips and just soak the whole gun in gasoline for a day or two. That will definitely take off any tape residue and won't hurt stainless steel one little bit.
Guys...NEVER use gasoline as a cleaner. Gasoline is too dangerous, and wasn't designed to be a cleaner in the first place. Depending on what you're trying to remove, denatured alcohol, naphtha or high-quality mineral spirits (like Prep-Sol) is effective and much safer than gasoline.