A friend uses a 7RM Tikkler as his primary. Viper 3-9x, handloads with 168gr Klassic.
It's consistently ~1" at 100 with this set-up, for 10-shots. Group in image below was after floating the barrel. Although I don't think he needs to shoot at 100 anymore, he still does every now and then and it's always 10-shots under 1", or very close.
The rifle is obnoxious from prone. He wears some sort of shoulder pad. 40-rounds from prone will take it's toll, and the scope has grazed him a few times. When I shoot it, I notice a good deal of hop. Videos of him show the rifle jumping off the front rest.
Last time we shot, he hit a 6"x8" steel plate at 610 yards twice in a row. Third shot was just off the edge of the plate. Not bad with a BDC and wind.