Ruger won't install any replacement barrel but the same type that the gun left the factory with; in other words, they will
ONLY install a 5.5" barrel on that gun.
There is/was a 7.5" stainless barrel on Gun Broker earlier today; that might be an option - although it will be an
expensive option by the time you have it installed on your gun!
I would personally use this as an
excuse, er
reason, to buy another gun...