One of the new differences was the feed, which now was a vertical 30 round box magazine, probably based on the German MP40. Although US troops were initially resistant to the looks and feel of the new weapon, it slowly gained acceptance, and its light weight and short length (with the metal rod stock collapsed) proved a perfect fit in many AFVs, including most US tanks. By mid WWII, the new weapon had replaced most of the Thompsons provided as personal weapons in tanks, and the Chaffee was amoung thse outfitted with the new M3. By 1945, over 606,000 M3 SMGs had been produced by a number of contractors and subcontractors. The M3's rate of fire was automatic only, between 350 and 450 rounds per minute, and the total weight of the weapon was only 8.15lb (3.7kg) compared with the M1A1 Thompson's weight of 10.45lb (4.74kg).
US tanker's uniforms did not change much in the five years between WWII and the Korean War. Indeed, most uniforms were taken from the earlier war's left-over clothing stocks. In the above US Army photo we see the typical one and two-piece herringbone twill fatigue overalls, usually produced in any of a number of grey-green shades of olive drab. Also worn by armored vehicle crews were the two-piece combat fatigues used by most US Army units, as seen in the first picture above. Although the WWII style crash helmets were still worn in Korea, these men are wearing the peaked OD fatigue cap preferred when crews were out of immediate danger. These Chaffee tankers (staged for the Army photo) are said to be holding a road intersection behind the lines in August of 1950. Not all M24s were withdrawn with the arrival of the larger medium tanks in Korea; a number of Chaffees were used for patrol and police duties. The crewman on the ground holds an M3 grease gun, while the tanker up on the driver's hatch cradles a .30cal M1 Carbine. This weapon was designed by Winchester, which then proceeded to work overtime to fill government orders that flooded in. Eventually, the company and others manufactured over six million of all versions of this carbine, the most manufactured weapon of any country during WWII. It was an extremely popular gun and although originally carried only by rear support troops, it found its way quickly to front line combat soldiers by 1943, including an occasional tanker. The M1A1, with collapsible wire stock designed for paratroop use, was even more popular due to its compact size and light weight of only 6.2lbs (2.8kg).
Additional Sources:
www.globalsecurity.org
www.onwar.com
mailer.fsu.edu
www.wwiivehicles.com
www.movieprops.nl
mil-trucker.narod.ru
www.rt66.com
www.piermodels.com
