FYI, WD-40 works well for removing residual tape mastic, and it won't bugger up a nice wood finish or attach synthetics. (That's about the only thing I use it for - it sure isn't worth much as a lubricant.)When I get ready to remove it, I use acetone to remove any residual glue from the tape and then clean and oil the gun.
For that matter, "stainless" as applied to alloy steels is a misnomer. In the engineering biz, we refer to these generically as "CRES" - for "corrosion resistant steel." Note - not corrosion proof.Just be advised that stainless steel used for guns isn't really stainless.
Most guns are 416 stainless which has a fair amount of carbon in it to make it heat treatable. While some stainless is not magnetic, this stuff is.
Be sure to wipe if off after you use it because if put up wet, it WILL rust, although it wont be as bad as carbon steel.