When I started working up a load for my 264 mag with 130ABs and Retumbo the only data that I could find was from Hodgdon 2011 annual manual. It listed a 129 gr Hornady bullet so I started with the staring load for it 63.5 grs and worked up in half grain at a time loads. I found that 67 grs was too hot for my rifle. I backed off to 66.5 grs. I ended up with this load. 66.5 grs Retumbo, cci 250 primer, cases made from once fired Winchester 7mm Rem mag cases, 130 accubond, COAL 3.450 which is 10 thousands off the lands. From my 27 3/4" Shilen 9 twist barrel I average 3350 fps and 1/2 MOA accuracy or better on average. This bullet is awesome on deer. I have shot a dozen + (lost count) from 30 to 400 yards and all have exited except one and all deer were DRT. I recovered one bullet from a buck at 111 yards shot on the front edge of the left shoulder and bullet was found against the smashed ball socket of the right ham. Bullet was a text book mushroom and weight was 87 grs.
When you load that bullet out long like mine is loaded it reminds me of a Saturn 5 rocket ready to go to the moon.