Nope, Lazz started his line of stuff by choosing distinct head size dimension. That would assure he could call them proprietory and not wildcats.
For a big case 30cal, the 416 Ridgy or RUM case will fill the niche. Even a necked down 338 Lapua or improved case. For the shorter mag, the WSM is probably the easiest/cheapest/most readily available.
The Dakota line of cases are also very interesting. As are the old standby Weatherby's.
Thanks ...I have a 300 rum being built on a p-14 now with a 33" tube ,but I have a real nice Mod 70 action that was a 308 and was wondering what I could do with it..Maybe a 308/6.5..Whats that called now days?.....Ole well play play........PlayPlay
(6.5/08) It's called 260rem, and it's an outstanding round. We have from a highpower match shooter from Mid Tenn who took 4th at Camp Perry this year with a Winch M70 action, 24" barrel in 260, and that was across the course. At 600 from a sling he shot a 199x11 and from what I've heard from the pits, besides that 9 he had a 4" group with iron sights. BUT, he's an outstanding shooter and could have likley done very well with an old drop breach 45/70.
The rounds works and works well, and now is factory supported, though you may want to neck down Lapua or Winch brass to stay away from the Remington. It may be fine brass, but I've had no luck with it in 308 or 223.