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Niketown NYC (March 1997)
In 1965 the Sterling Armaments Company developed a new version of their successful submachine gun. The S11 represents an effort to modernise the reliable Sterling submachine gun and compete with the new Heckler & Koch MP5.
While George Patchett, the original designer of the Sterling, was still working with the company in 1965 the design of the S11 was overseen by Frank Waters, Sterling’s chief designer and David Howroyd, Sterling’s works director. The design takes cues from the Israeli Uzi, a contemporary of Sterling’s original weapon.
Unlike the original Sterling submachine gun, which the British Army adopted as the L2A1 in 1953, the S11 had a stamped box, rather than tubular, receiver. The S11 takes on an almost Uzi-like appearance, however, it retained the Mk4′s excellent curved, side-loading magazine. The S11 moved the position of charging handle from the right side to the top of the receiver (see image #2). It appears that Sterling added a sliding dust cover to prevent the ingress of sand and dirt.
Sterling added a plastic foregrip replacing the earlier weapon’s perforated barrel jacket. The new foregrip allowed to attachment of an L1A1 rifle bayonet, it also appears that the stock folds into a recess in the grip. The S11 moved away from the original Sterling’s design with its barrel fixed in the receiver by a barrel nut similar to that used by the Uzi.

Sterling L2A3 (source)
Due to the S11′s folding stock its sights are offset to the left, to bring them more in line with the operator’s eye. The box receiver necessitated a new stock design with two pivoting points either side. The S11, like commercial production Sterlings, was parkerized and painted with black crackle texture paint.
The S11 retained the Sterling’s trigger and fire selector mechanisms and a similar pistol grip profile. However, the new weapon had a new type of plastic grip was incorporating what appears to be a prominent grip safety - similar to that seen on the Uzi. As image #4 shows the the initial prototype was able to fit both the L1A1 rifle bayonet and the No.5 bayonet. Whether this is a feature that Sterling would have retained for production models is unclear.
The experimental S11 had a series of defects and interconnected problems, none of which were unfixable. These included a loose top cover, feeding problems and trigger failures. Sterling decided that rather than sink money into fixing the S11′s defects and retooling for manufacture it would be more cost effective to retain the current design.
Sterling gradually lost market share as the Sterling was over taken by more modern designs. Sadly, the S11 apparently suffered from reliability problems and lack of military and commercial interest scuppered the project. Sterling produced a single prototype, serial number EXP 001, which the company later gifted to the Ministry of Defence’s Pattern Room in 1989. Today the S11 is held by the Royal Armouries’ collection.
Sources:
Centrefire automatic submachine gun - Experimental Sterling Model S11, Royal Armouries Collection, (source)
The Guns of Dagenham, P. Laidler & D. Howroyd, (1995)
Weird and Wonderful, Royal Armouries Blog, J. Ferguson, (source)
The Sterling Years, J. Edmiston, (1992)
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