I believe the issue is the receiver and then the follow-on parts. Springfield made a M1 Garand "clone" out of a cast receiver for a while (I think it's no longer available). Other than Fulton Armory (which uses USGI receivers), my understanding is that it's cost-prohibitive to make a a true Garand clone.Am I the only one who wonders why some bright spark doesn't start manufacturing brand-new, MIL-SPEC and/or "march grade" M1s? Seems like the market interest would surely be there...like any one of the hundreds of 1911 clones currently available.
ETA: Chuck beat me to it.