What do you think of a

[sneaky one]

If IIRC, the 243 wssm, is more like an Ackley improved 243-3400 fps.
Once you get past 3000fps., that's where the bbl. wear accelerates.

I chatted with Mike Milli from D-tech last year of all his calibers. I may get up there this spring to have him build me a-.35--.375 cal. bruiser, bbl/, & bolt for the AR.

The 6mm turbo looks really good.