Don,
If was getting a new barrel, I would get a .30-06. It's easier to load down than it is to load up. That being said, the .30-06 is more versatile than a .308. According to Speer #10, the .30-06 is 200 fps faster than the same 150 gr bullet in a .308 with the same barrel length. If you want it to shoot like a max load .308, just reduce the load by 4.0 gr, but don't try it the other way around!
Paul:
Here's another reason to "update" to a current reloading manual...page # 281 Speer reloading manual #13... and I quote
Lab Notes...
We've had many callers ask why the 308 velocities shown are
EQUAL to or better than some of the 30-06 velocities shown a few pages ahead They ask if it's a mistake.No it's real,and there are two reason.
First,a compact case and a higher pressure limit give the 308 and edge with bullets up to 150 grains.Things are about equal with the 165 grain bullets,but the big 30-06 case's ability to hold a lot of slow burning powder gives it the upper hand with heavy bullets.
The second reason is the sporting rifles used to record final velocities.Both have 22" barrels and were bought at the same time.The 30-06 sporter posted velocities about 50-100 ft/sec behind the 24" pressure barrel.That's normal.On the other hand,the 308 sporter was consistently
equal to or slightly faster than the pressure barrel(Speers italics). Like we've said several times,all sporters are different! See "Why Ballisticians Get Grey" in the handgun section......
Now as far as the 30-06 being more versital...I agree with you...the 308 can't handle the real heavy weights like the '06 can with the 180 grainers and up.. you'll have the same advantage as the 308 does with the 150 grainers and below...
Mac