Check what twist your barrel has first. This will determine what bullet weight you can use. You need an 8" twist to stabilize most 140s. I have a 9" twist and use 130 gr Nosler Accubonds with Hodgdon Retumbo powder. My rifle likes this load.
I use Winchester 7mm Rem mag cases to form my 264 Win mag cases. Just run them in a FL sizing die. This is my load. 66.5 grs Retumbo, CCI 250 primer, 130 Accubond seated 20 thousands off the lands. My Rem 700 has a 27 3/4" Shilen barrel and I get 3350 fps and under MOA accuracy. This bullet WORKS GREAT close up or far away on deer. I have only recovered one bullet out of 20+, lost count, deer shot. It was from a buck at 111 yards almost facing me. Bullet entered front edge of left shoulder smashing it and made soup out of the vitals and was found in the right ham after smashing the ball socket. Bullet was a text book mushroom and weight was 87 grs. Impact had to still be over 3100 fps. I have killed deer from 30 yards out to 500 yards and all have been DRT. If you shoot slow and let the barrel cool good a 264 Win mag will last as long as any 7mm Rem mag shot the same way. I like my 264 Win mag MUCH BETTER than the 7mm Rem Mag I used for a while for deer. No matter what bullet I used in the 7 mag deer would run off a ways. Same shot placement with the 264 mag BANG FLOP.
