This is an excellent example of a late 1950s production, experimental M1 Garand rifle chambered in the experimental Duplex cartridge of "22-06". This specific rifle is marked on the barrel as a "Shop Model" which may have indicated it was used for some type of final evaluation of these rifles. In the mid-late 1950s the Army developed a series of experimental cartridges using hyper-velocity and multiple projectile bullets with the intent of improving hit probability. This example is one of those test rifles intended to prove out the design concept firing a "duplex" cartridge. This cartridge (22-06 Duplex) was actually a 30-06 case necked down to 22 caliber that had an elongated neck which held two 50 grains bullets (stacked on top of each other). The rifle itself was manufactured by Springfield Armory in 1957 and it has the original and all correct corresponding parts. The barrel as noted is in 22 caliber and interestingly it is marked on the right underside with "MODEL SHOP SA/XO 8142-9039/SAF 38356/CAL 22-06/3-59". The bolt is marked "SA 65282871-SA/YO1" and the operating rod is marked "6535382 SA". The complete trigger group is all correct late post war SA production that is correctly marked. It is fitted with the standard gas cylinder with a high hump gas cylinder lock and a four-slot gas plug marked "BS". It is fitted with a standard front and rear sight set. It is fitted with a standard walnut stock and hand guard set. The stock has the DOD cartouche on the left side with a single circled "P" proof in the pistol grip area.

Excellent plus with 99% of the parkerized finish overall with a hint of finish loss on the right receiver rail. The stock and handguard set are also in excellent condition with a clear sharp cartouche and firing proof with only a few very minor scratches on the right side of the buttstock. A super looking, rare experimental M1 Garand rifle.