6mm is good and many will run those speeds. I ran a 243 at those speeds. I think the 2 I’m most interested in for higher speed is the 6-284 and 6 prc. I know a few guys who run the 6 prc and it’s wicked and on my radar. Thinking a 20” barrel with my can would be good, 110ish at 3300-3400. We’ll see, I have a creed and prc that are used for hunting now and both are a pleasure to shoot.Presently looking at putting a longer range rifle together. Looking at a 6mm of some type, that puts out about 3200 fps in a 115 gr. bullet with a 26' barrel in 7.5 twist or there about. I haven't settled yet.
I would say there been some good work done out there.