He was comparing it to the mini-30 which is 7.62x39.
There are 7.62x39 uppers for ARs also. The reloading handbook said not to expect 2.5 inch accuracy for it. M1A match is probably the most accurate but personal preference seems to rule here.
25 posted on 02/23/2018 6:17:18 AM PST by mountainlion
(Live well for those that did not make it back.)