The 916s, in the early 1970s, were the first generation of the guns produced after S&W bought the Noble gun Co. shotgun tooling & parts, and are essentially Noble's Model 66 with the S&W name on them. S&W first called these ex-Noble designed guns the "Eastfield" model 916. They had fixed barrels, in lengths from 18 in. to 30 in. and in 20, 16 & 12 ga. Original prices were $98.25 to $122.50. Later the Model 916T ( T for takedown) came out with interchangeable barrels. Your friend's 18 in. barreled Model 916 is the "Riot" version offered for Police & Military uses, and were available with, or without, an extended high capacity magazine tube. Ed.