I just tried a load last weekend for my buddy's 22-250.
It's a factory savage model 16, 22" barrel, 1 in 12 twist, 53 gr Vmax and Hodgdon Benchmark.
I too wanted to try the 53 gr Vmax for the awesome BC. We're not getting near the velocities you are shooting for (our load validated @ 3350 fps). But is it good to 600 yards?? Heck yeah!
On paper we had 1/2 MOA @ 200 yds and sub MOA @ 600 yds.
To further validate our velocity I took it out monday and demolished milk jugs @ 500 and 625 yds.
I have heard much the same as has already been said, about the 1 in 14 twist barrels not stabilizing. The 1 in 12 we're using works fine though.