My Father has a .270 Wby Magnum , Mark V , beautiful walnut stock , original thin tapered 26" barrel , that I have reloaded for him since 1976 .
Norma MRP powder ( slightly less than maximum Norma reloading guide charges that start at 69.8 gr. and max load of 72.8 gr.) , Fed 215 primers , 150 gr. Nosler Partitions and Ballistic Tip bullets @ 3308 FPS . NO pressure issues , and accuracy is always less than .75MOA .
I have never had any issues with temperature sensitivity .
I did open up the barrel channel to free-float the barrel .
If this rifle had a faster twist barrel to be able to shoot the newer high BC bullets , it would be capable at any distance .
DMP25-06