Hej 378Canuck
Well, you could not get two more different calibres for "our comparison"!
Mine was a .222 Rem, yours the mighty .378 Weatherby.
I too (now) use nothing but Lapua brass in my .222 -- it is amazingly good!
Actually, as a 3 decade handloader, I hate to admit it, but I hate a devil of time even
matching the accuracy of the Lapua FMJ factory rounds that I purchased to get the brass to reload.
My best tailored reloads with Norma brass just neck sized were still less accurate than those Lapua factory loads.
I have a .375 H & H so I am not a stranger to recoil, but I have fired a .378 Weatherby -- I salute you and your rawhide-covered cast iron shoulder!
John (Canuck in Sweden)