the US Navy converted a number of M1s to 308 by putting in chamber adapters but they had a nasty habit of extracting with the spent casings so they started getting barrels already chambered in 308, CMP has these barreled actions for sale right now and they also offer a special grade garand with new stocks and converted with new criterion barrels in 308 and have magazine blocks to prevent accidental loading of 30-06 into them.
ignore my complete lack of capitalization. I still have no problem correcting your grammar.
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