Re: caliber change
With the velocities that this case is capible of the
107 SMK , 105 A-max , 95 or 105 Berger VLD's will all get you to 1000yds pretty easy. I'm not to sure how big your Roo's are or how tough they are to kill but the 105 A-max will kill smaller deer and Prong horn here in the US out to 500yds.
I'm haviong a 260 built right now and from what several guys that shoot it (and that I respect their judejment) say that it should be an easy 600yd deer gun with the 140gr
A-amx launched at 2800fps.
As for the throat erosion , I don't think that it will be nearly as big of a problem with the 243WSSM as with the 223WSSM. I'd order a quality barrel in 243 with a 1-8 twist , order it with a 3-4 " shank that way after a couple thousand rounds you can set it back and rechamber it.
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