With everything trending toward heavier bullets and fast twist barrels - what can I do with a 14" twist 6mm barrel?

I have a Lilja 14" twist barrel in 243 WSSM that has been shot very little. I can't seem to sell it, so I want to put it to use. I was thinking of cutting off the chamber and making it a 6mm AI varmint rig. What is the heaviest bullet that will stabilize in this barrel??
If I go to a 6 PPC or 6 IMHSA, will I have to go with a lighter bullet?

A former acquaintance used a 6BR with 65gr VMax for PD hunting and I believe his was a 13 or 14 twist. With your home elevation and the added velocity of the 6AI I would bet you could go a bit heavier. Of course length will be the deciding factor. I found an article on 6BR that showed some success with with the 75gr VMax at 3800fps in a 6mm AI.

http://www.6mmbr.com/gunweek042.html

I have a 14 twist Kreiger chambered in 6-284 that shoots 70 BT's at 3800+ into very tight groups. Might be a good place to start

My original intent was to use this for a 6-284. I do have a 6-284 but with an 8" twist and 30" barrel. Once I cut the WSSM chamber off this will be 23". I am at 5100', but there are very few PDs on this side of the state (good number of coyotes tho). I'm guessing the elev is similar on the east side of I-25, maybe 1000' lower.

I don't waste what is a limited amount of barrel life on many prairie dogs but it is something to see on coyotes.

If you stay off the fringes and bone it isn't all that destructive on fur. ( Most times!)

Remember that you will either need a new bolt or bushing the bolt on yours.

I thought it was just a spare barrel he wanted to cut the shank / chamber off and re-thread. Not a rifle chambered in 243 WSSM?

Yeah, I just have the barrel.

my -12 6mm likes 70grn flatbase the best.

cci benchrest primers and varget.