Just wondering if anyone has necked a 338Lapua upto 50cal and if so what sort of velocities you are getting? Does it match a 500Jeffery?
Thanks

Well, if I remember correctly. the .338 Lapua is the .505 Gibbs necked down, so I guess you're talking about going full circle back to the original cartridge.

George

George
I have a 338 case and it is about the same length as the 500Jeffery with the rim dia of Weatherby/Rigby so if it is necked down anything it would be Rigby, also shortened.

Sorry but the 338 lapua is "based" on the 416 Rigby but the web is much thicker to alow for the higher operating pressure. These cases can be made in to 416 Rigby's. Yet,the original 416's should not be made in to 338 lapua. Now the 408.Chyann or Chytac is baised on the 505 gibbs

lapua is a reworked rigby... or beltless weatherby...

.475 is about as big as I would go (then it would be a 470 mbogo)

jeffe

Well, I suppose you could make servicable Rigby's from the Lapua, but you might miss that almost .2" on the end.
I drew up a 50-cal Rigby case, and it had more headspace than the Nyati or the 400 Whelen, and yet everyone tells me it will cause unreliable ignition, headspace issues, etc.
The Lapua would be a fair amount shorter, especially after all that necking up (unless you could find cylindrical), but you can check out the 500 A-Square for an idea of what it might do. The Rigby and Weatherby case are about the same, and the A-Square is the necked up Weatherby, donchano.