RE: 125 Grain 30/06 load well suited to deer?
I concur on the 130 Xbullet. I shot them for 4 seasons in my Warbird (3900+ fps) and never once had even a hint of failure with any shot angle and distance you can name!
Dont get too caught up with "theoretical numbers" like sectional densities and to some extent even ballistic coefficients. Dead deer dont have calculators! You should be able to drive a 130 Xbullet in the 3200ish fps range from a 22"-24" 06. But also be realistic, you wont see over two inches of difference between it and a good 150 all the way too 400+ yds. But the 150 will retain a lil more velocity which adds up with more power.
I wouldnt go after 350# Canadian whitetails @ 400yds with a 130 from an 06, but for most typical deer hunting you will be ok. That bullet will out penetrate 150s like Partitions, Ballistic Tips, CoreLokts etc...
Good luck,
RA