Not counting my savage 11FL in .223 (which will definately shoot under 1"), I have 2 others, a Rem 700 in 270 thats about 30 years old and a Browning Micro Hunter in 7mm-08. The Browning had a lot of work done to it to get it to shoot. A bedding and trigger job were necessary. Before that it couldn't shoot better than 2 1/2" which was fine but not good enough for me.
I have a Ruger 77 in 300 Win Mag that can do it but only when everything else is perfect, including me. It averages about 1 1/2".
But like some of the other guys were saying, there are a good amount of rifles that can do it but the shooter isn't up to it. Some days you just 'get in a groove' and shoot those tiny groups.
My last outing, my Savage 17HMR with a heavy barrel put 5 rounds into a hole that looks like a .30 cal hole at 50 yds.