There is only one .30-06 M1 Garand and only one .308 M1 Garand Criterion barrel offered at the CMP store. They are made from 4140 alloy CHROME/MOLY steel, meaning there is about 1% chromium and 0.2% molybdenum in the steel alloy. It is not chrome-lined. I have two of them and can verify that for you.
If you want to buy a chrome-lined Criterion barrel, it will have to come from some other source than the CMP and it will be fully chambered to a middling chamber length value.
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