I like the 50gr bullets like Hornady V-max as well as you guys do, but the 53 is where it's at. Higher BC's than the 60gr v-max. Even bests the 55. If your 14 will stabilize that bullet, that would be the first one (besides the 50) I'd suggest. Powders like H380, AR Comp and H4895 work well for that bullet weight.
You are limited to bullet weight, based on your twist rate, but there's still a lot you can do with a slow twist 22-250. I have a couple 14" twist 22-250's left and one is a Tikka Varmint like the OP's. It only gets fed 53's now. They have been pretty acceptable, even out to 600 yards.
The last time out with my Tikka Varmint 22-250 and the 53gr V-max load I was talking about:
Other times I've managed sub 1" groups at 400 yards with that rifle/load combo. And still maintained less than 3" groups at 600 yards. YMMV..
I've actually used this rifle and load on some long range varmint silhouette shoots and it does surprisingly well. Able to hit the 611 yard steel rabbit pretty consistently. Doesn't shoot as well as the creedmoor, but still does better than you'd think for such a light pill.