Armalite was a company founded as an offshoot of the Fairchild Aircraft company, and working with aluminum was their specialty. This was a fairly novel material to the arms industry, and they were able to exploit it fantastically in the AR-10 and AR-15 rifles. The AR15 rights were sold to Colt in 1959, though, and Armalite went in search of other guns to market.
One of these was the AR-17, introduced in 1964 to the commercial market, aimed at hunters and sport shooters. It was a short recoil action with a 10(!) lug coating bolt similar to the earlier Armalite rifles and a 2-round capacity, chambered for 2.75” 12 gauge shells. It didn’t have a magazine so much as a single round lifter/elevator in addition to the chambered round. Most importantly, it was a nearly all-aluminum gun, weighing just 5.5 pounds (2.5kg). Only the barrel extension and bolt were steel, plus a few small parts. The receiver and barrel were hardened aluminum, and the furniture was foam-filled Nylon. The was truly the shotgun from The World of Tomorrow!
Unfortunately for Armalite, being extremely lightweight was not necessarily a god thing in a shotgun. It was certainly nice to carry for long periods while hunting, but short shooters found its heavy recoil to be punishing. The light weight also brought complaints that it did not swing well. And finally the limited 2-round capacity, while not logically a problem for the intended uses, was a turn-off to many potential buyers. Parts for 2000 of the guns were manufactured in 1964 and 1965, but only about 1200 were actually assembled and sold. The gun was a commercial failure by all measures.