Most of the following taken from Scott A. Duff's book _THE M1 GARAND: WORLD WAR II_....all facts are his, some of the conclusions my own, in any case here's my 2-cents on the subject. You can believe whatever you wish, but anyone telling you the stubby little Garand they're trying to sell you was made for use by treadheads is full of it....trust me.
Sorry fellas, there were many interesting variations of the M1 Garand experimented with during World War II....MOST never saw active duty.
The T26 (so-called "Tanker Garand") is a very good example, along with others like the U.S. Carbine, Cal. .30, M1E5 - a short barreled Garand with a metal pantagraph-type folding stock that some thought might see paratrooper service....it didn't. Another good example was the U.S. Rifle, Caliber .30, T20E2 - an M1 modified to take the 20-round BAR magazine and capable of firing either semi- or full-automatic. Some 100,000 were ordered from Springfield Armory in 1945, however the two A-Bombs made the point moot and program was cancelled after only 19 pre-production rifles were made...most of these remain at the Springfield Armory National Historic Site to this day.
SA's efforts to make 18" barreled T26 Garand version had nothing at all to do with tanks or any other tracked vehicle...the name "Tanker Garand" came about many years after the end of WWII when commercial concerns discovered it was an excellent gimmick to use when selling their own made-up Dwarf Garand version....it's still working today.
"The fighting in the Pacific Theater of Operations demonstrated the inability of the .30 caliber carbine ammunition to penetrate dense jungle foliage. Similarly the length and weight of the M1 [Garand] rifle also fell under criticism. The obvious solution seemed to be a short barreled M1 rifle.
In the fall of 1944 the Pacific Warfare Board ordered an ordnance unit of the 6th Army in the Philippines to make up 150 shortened M1 rifles for testing. Colonel William Alexander, head of the Pacific Warfare Board, requested that the Ordnance Department manufacture 15,000 shortened rifles for the arming of airborne troops. He dispatched a special courier to deliver at least two of these shortened rifles to the Ordnance Department in Washington, D.C."
Scott goes on detailing how these two rifles made their way to Springfield Armory for testing. There it was recognized as almost the same M1E5 variant SA developed in early 1944, 'cept it retained the wooden USGI stock instead of using a folding metal stock.
The end of the war in the Pacific also ended the project, but not before a military evaluation of the T26 Garand variant was made....in part is concluded..."We all loved the little gun, but it had a defect which we all felt made it totally unsuitable for a combat weapon with standard M1 ammunition. The muzzle blast was terrific, in the darker forest it was like a flashbulb going off. Even in the sunlight is was obvious." The recommendation was to cancel the project...it was.
What happened to the original 150 rifles (more or less) built by the 6th Army for testing? They were *supposed* to be converted back to the original M1 Garand configuration....were all re-converted? This is one of those little mysteries that no one will ever know for sure, however it is well known that none of the T26 Garand variants were ever accepted into the government's inventory for combat usage.
Bottom line....any T26 "Tanker" Garand you see for sale in the commercial market is as good as any other, regardless of the caliber it may come in - .30-'06 or .308Win/7.62NATO. It has no historical value of its own and has been modified from an original M1 Garand by a private civilian gunsmith or a commercial firearms company. I own one myself, a SA USGI M1 Garand built in April, 1943 that I had converted to T26 specs by gunsmith Bruce Dow of A & B Dow, Inc. located in Florida. It has a .308Win barrel and is a hoot to shoot; a real fun gun....muzzle blast and all.
Hope this helps shed some light and corrects some of the sales hype.