I have three M721's and two M722's. Would love to find a M722 in 222.
As side note to the posts, in 1958 the 721/722 went 22 inch bbls and eliminated the bulge for most calibers (although some calibers apparently still sported the longer bbls).
My latest 721 is a rusty, pitted 30-06 that went though hurricane Andrew. But amazingly the bore is good and it still shoots well. So I guess I'm going to bead blast and Cerakote it to make it halfway presentable.
Because I like the 700 safety lever more, I fitted the rifle with a 700 trigger (which required filing the tang to clear the 700 lever).
Picked up a Leupold 3x9 cheap, and my plan is to make the 721 into a "Camp Rifle".