I have bought some barrels either on ebay or Gun Broker and have had them slip right on to some of my L.C. Smith hammer guns. One barrel is from a Grade 1 and the other was from another hammer gun.
Hammer guns were all built on a Regular frame, hammerless after 1907, some were built on a FW frame (Featherweight).
Since these were production guns, all were hand fit and the jigs used to align the barrel loop were all very close in tolerances.
The hardest thing to fit is the for-end to the bastard barrel.
It is better if you can find a set of barrels within a few years of your serial number +/-.
Naturally, Regular frame barrels will not fit a FW frame and vice-versa.
