This is an excellent example of a mid-production Colt Model 1921 submachine gun with the desirable 1928 "U.S. Navy" over-stamp markings. This example is listed in the book "Colt Thompson Submachine Guns" by Herigstad, on page 842 as originally having belonged to the Hancock County Sheriff's Office, Bay St. Louis Mississippi, then sold or transferred to the Law Enforcement Equipment Co., Nashville Tennessee, (6/84), then offered for sale by the Sturmgewehr Company Sunset Arms Macon GA. (5/06). This model originally was offered as the M1921AC , however based on the successful use by the USMC in the China and Nicaragua campaigns circa 1926/28 and based on their recommendation, the Auto Ordnance Corporation modified them by reducing the rate of fire to approximately 600 rounds/min, and added a Cutts compensator to the muzzle to help reduce muzzle climb during automatic fire. So in 1928, Auto-Ordnance Company remarketed the earlier Model 1921 SMGs with the "U.S. Navy" markings to help improve sales and pique interest with police and government agencies. These Thompson SMGs were probably some of the finest submachine guns ever produced and had superb machining and hand fitted parts. It has a distinctive deep rich blue metal finish with the bolt remaining in the white and a walnut foregrip, pistol grip and buttstock. This example still retains the distinctive early features, such as the short 10 1/2 inch barrel with cooling fins, ported Auto Ordnance/Cutts barrel mounted compensator, the vertical pistol grip, the detachable buttstock, and the fully adjustable Thompson ladder rear sight graduated from 00-600 yards. The receiver is marked "U.S. Navy/MODEL OF 1921" with the number "1" over stamped with a number "8" in the markings with the standard Thompson/Colt Submachine Gun model, caliber and address markings on the left side. The top of the receiver also has the "THOMPSON/Bullet" logo. The right side has the five lines of patent dates followed by "AUTO-ORDNANCE CORPORATION/NEW YORK, U.S.A". The lower trigger housing is also correctly stamped with the matching serial number of "8618". As noted, it a walnut vertical foregrip, rear pistol grip and buttstock. This example is complete with two original Auto-Ordnance/ Thompson "L" type, 50 round drum magazines, three 20 round stick magazines, a spare bolt assembly, two new recoil springs and washers. It is all housed in a reproduction FBI style leatherette case with brass closures and a brown leather handle. Additional information related to the magazines: One Seymour drum magazine, one Bridgeport address marked drum magazine, and one stick magazine with the 1920 and 1921 patent dates.