I've had most of them including a couple of .340's and 3 different .416's, 2 custom barrels, 1 triple magnaported, 1 factor break and 1 clean barrel, cropped to 25 inches which tended to be the most accurate of the three and generated the highest velocities.
It took me 12 years to shoot the barrel out on the .257 but that included 600 of the rounds at range time and load development, the balance on game. It seemed to kill more instantly than the .270 even when lighter 110 grain and 130 grain bullets were used. Normally I favor a jump in caliber before more velocity but once you get towards those mid 3000's in velocity, you start witnessing a cartridge that breaks all the common opinions. The .257 is exceptional on medium game and if capable of whatever the rifleman is capable.
The .270 was its equal for one shot drops when using 130 grain CnC bullets but as the .270 Weatherby had been used and very successfully on water buffalo, lots of them, using 150 and 160gn Partitions, I also tried the cartridge which some heavier weights for caliber and found it worked well on the mostly medium sized feral game. Never saw a 7mm Weatherby but have used the Remington and STW on game so they are much the same and equal to the .270 Weatherby at least on the game I hunted.
The 300's and .340 couldn't really be tested for any difference or benefit, nor could the 338/378 I had on Aussie game as the aforementioned cartridges sufficed more than adequately for what we had and red deer did not prove as tough as born wild brumbies.
Once you get up to the .378 Weatherby you need a marketing hat to convince yourself you need it, meaning a use for it because the .416 and .460 can cover the same ground. I used the .416's from 1990 to 2002 and never had a complaint. The .460 I used a lot longer than that so often had them in the field at the same time as well as several .458's. Never met and animal that didn't meet its match with those.
The big surprise is accuracy. If you can master the big Weatherby's, they offer surprising accuracy where cloverleaf groups are absolutely not rare.
I think the 240 is as good as contributors state, it does drop deer sized game cleanly and in the 26 inch barrel is relatively soft on the ear. In a practical sense though it offers far less than the standard .25/06 due the cost of brass, case capacity, bullet weight range. I've had both and still have the .25/06 which also has the 26 inch barrel.
Which is best? Hard to provide facts over opinions but the .257 as a pure hunting rifle is good, the .340 is really proving your money's worth if you hunt larger animals but the secret here is to get the barrel Magnaported. It doesn't produce any noticeable increase in muzzle blast, holds the muzzle lower to point of aim and definitely feels like there is a recoil reduction. Add to this lot the .460 as you can load it to your own recoil level and still have reasonably common loading components. Brass lasts forever and the medium 4064/Varget/ 350/760 type powders work very well. If you want to travel light, the .416 can be bought or built in a lighter package but you will need to choose between velocity, recoil and a break of some sort. I probably killed more animals with my first .416 which had no break, but I was half my age and half as smart back then.
If you want 2, I'd recommend a 7mm and a .340.
If you want one, get the .257.
Last edited by AussieGunWriter; 11/30/21.
