Re: Best long range cartridge that fits in a Mark V
I have both of the ones that were mentioned the most. I have a Hall Express in .338 Lapua Improved and another one in .338/378 with the same length barrels.
In short, when shooting to the full potential of the gun, shooter and components, only 12 fps seperates the 338/378 from the 338 Lapua Improved.
Lapua brass lasts much longer and is more consistent for a longer period of time as far as neck tension is concerned. I have never ruined a Lapua case primer pocket..... But I have had some of the Weatherby cases get weak in primer retention.
If you were not interested in the improved version of the Lapua case then I would go with the Weaherby. But, if you were willing to do the improved version, the Lapua would get the nod from me. Again, I have both and even a 30/378 Weatherby.
We use the big Weatherby rounds to test the high BC HAT bullets. We use the Lapua Improved cases to hunt with.
Are you more concerned with the second and third shots or more focused on the first one?
Almost forgot, 100 Weatherby branded cases will run you almost $289.99 and the same number of 338 Lapua cases will run you $214 both from the same source. Basically, you can get (500) 338 Lapua cases for the same price that (375) .378 Weatherby cases will cost. Finally, the Lapua case is more efficient as it gets the same performance with less powder.
Also, I follow my own advice and I have right at (2000) 338 Lapua cases and maybe (120) 378 style cases counting up all three variations. When the 378 brass runs out, the barrels get rechambered into 338 Lapua variants.