Hornady factory ammo is measuring 2.945 for both the 143ELDX and 147ELDM per link above.
Just measured my Ruger 338 RCM Mag box and its 2.91"
Was thinking of buying a Ruger LH 300 RCM and re barreling it but looks like its mag box OAL is short?
Measured my LH 300 WSM mag box and its over 3" .
So thoughts on above please?
By no means an expert or even that well-versed in this area, but I have been researching this cartridge quite a bit. One theme I keep running across on the various long-range shooting boards is that the WSMs are the best candidates for re-barreling to 6.5 PRC. Perhaps your findings are why they're saying this?