PJGunner, I agree with you about 52grs of H414 and a 140gr. bullets, at least in my rifle 49grs IS max. With 52grs I'd be getting over the top pressures. But the 7x57 is one round with a lot of differing chambering dimensions, but still were it me I'd approach that load suggestion with caution.
You need to approach any recommended load with caution. My load is "my" load. But... it is also a recommended load in at leasy one one reloading Manual I have seen (Actually 52.5gn).
I too, have owned a Model 70 in this chambering and I agree with you that 140's maxed out at about 2800fps. You will find this is more due to the tight twist in that rifle which was designed to shoot the only factory load Winchester made at that time, which housed the 175gn RN bullet.
In my Model 70, the most accurate load I tried was using 175gn Sierra BT's over 50gn of IMR 4831 for 2440fps. With the 140's, my best load was 51gn of IMR 4350 for 2846fps using the Nosler Solid Bases.
Hope this helps,
John
