I perused the 1973 Gun Digest (your caveat "around" duly noted) but found no mention of the Remington Models 721 and/or 722 rifles.
That's because the 721/722/725 rifles were long out of production by 1973. Remington phased out the 721/722 in 1963 and introduced the 700 in 1964,
Every issue of The Gun Digest is full of articles dealing with everything from matchlocks to ray guns. It would not be at all unusual, for instance, for the latest 2012 edition of The Gun Digest to feature an article on the Remington 721/722 rifles. I looked at the 1973 edition of The Gun Digest only because that's the issue that poster Itc444 thought he might have read "Jack Conner" (I'm sure he meant to say Jack O'Connor) say that the "Remington Model 722 was the best commercial rifle ever built." Which, as I pointed out, simply wasn't true. No doubt Itc444 read this claim in some magazine or book somewhere along the line but, as he now says, he probably misplaced the book and is unable to find the source of his quote.