Fact Sheet #5
THE M1 "TANKER" MODIFICATION
The so-called "Tanker" owes its existence to the long-standing dissatisfaction with the range, lethality and foliage penetration ("brush cutting") capabilities of the M1 carbine. A few statistics explain why this is true: the bullet used in the .30-06 M1 (Garand) rifle weighs 150 grains; fired with a velocity of 2,740 feet per second (fps), it develops 2,170 foot-pounds of energy at 100 yards. By comparison, the bullet fired by the M1 carbine weighs 110 grains; at a muzzle velocity of 1900 fps, it produces only 600 foot-pounds of energy at the same distance--not much more than a quarter of the Garand. Thus, the temptation to substitute the greater fire-power of the M1 rifle is understandable, although reducing the barrel to carbine length would sacrifice some of the gain in power.
The Ordnance Department was basically unsympathetic to these field complaints, maintaining that the carbine and rifle were intended to serve separate and distinct purposes. In 1945, with fighting raging in the dense jungles of the western Pacific, where "brush-cutting" ability was important, the Pacific Warfare Board took matters into its own hands. It ordered an ordnance unit of the 6th Army in the Philippines to make up 150 shortened M1 rifles for testing. These rifles were cut to carbine length, making them short enough to carry comfortably in the jungle or to fit into a tank. This, apparently, is the origin of the term "tanker" Garand, which was never officially adopted and is somewhat puzzling in that tank warfare did not figure prominently in the Pacific Theater.
Col. William Alexander, head of the Pacific Warfare Board, obviously thought the "short Ml" was the answer, for he requested the Ordnance Dept. to make up 15,000 short rifles. To facilitate design of the new weapon, he sent one of their rifles by special courier to the Ordnance Dept.
When the "short rifle" arrived at Springfield Armory, engineers recognized immediately that they had done the same thing a year before when they had developed the M1E5. The only difference was that the E5 had a folding wire stock and was intended primarily for paratroops. All they had to do was to pop off the trigger housing, remove the folding stock, and install the action on a standard M1 stock. However, since the receiver of the earlier experiment was marked M1E5, the model shop took a new M1 receiver and built
it from ground up with modified parts. This rifle, along with the rifle from the Pacific Warfare Board, was shipped to Aberdeen Proving Grounds for tests. By now the "short rifles" had been designated T26.
The results of the testing showed that the weapon suffered from lack of reliable function, excessive recoil and excessive muzzle blast. Function problems were traced to: (1) the rework needed to produce a shorter operating rod changed force angles, causing the rod
to bind occasionally; (2) the shorter spring length caused premature spring failure rates; (3) the pressure port was closer to the chamber and permitted increased volumes of unburned powder residue to foul the gas system. Increased recoil was expected, but muzzle blast was, to say the least, spectacular. When fired with standard military ball ammunition, the muzzle flash and dust signature was unacceptable. (Flash hiders and muzzle brakes weren't being used then.)
Because Germany had already surrendered and victory in the Pacific was close at hand, and because test results were unsatisfactory, it was decided to cancel all orders before any T26 rifles were actually produced. The only T26 made at Springfield Armory was damaged during testing and possibly salvaged for parts. The Pacific War Board prototype was returned to Springfield and placed in the museum. This is the weapon that appears in standard published photos. In reality, there were only 151 "Tanker" Garands made. Few of these probably survive. Some may have gone home in soldiers' duffel bags, but most would have been stripped and rebuilt to normal configuration in the years following World War II.
Identification of a legitimate "Tanker" is difficult. All specimens would have been built from rifles in used condition; therefore, the serial number range would reflect that. Numbers would probably be lower than 3,500,000 and could not be above 3,800,000. The barrel date, of course, would be no later than early 1945.
Also, the receiver is marked as a normal M1 and would be of either Springfield Armory or Winchester manufacture. Judging by the specimen in the Springfield Armory Museum, workmanship was marginal. The barrel splines look like they were hand filed and much freehand saw and file work shows up.
Despite the insignificant numbers of "Tanker" Garands actually made by the Army and their complete lack of success, their popularity grew. By the 1960s, when Garands became readily available through government surplus channels, a number of enterprising individuals began providing customizing services for M1 owners. One of the more popular services was, predictably, making "Tanker" versions. In those days a nice M1 could be obtained for $79.95, so a $40 "chop job" was not considered to be an offense against a collector's piece.
Text & images: Springfield Armory NHS, US NPS