.308 vs 30-06 bullet weights

[bushwhacker]

We were talking at hunt camp with a hunter who presently only owns a shotgun and bow who is thinking about buying a rifle. He would mostly use it for deer, but might try moose hunting. We discussed .308 or .30-06 and I made the statement that if you weren't reloading it probably made no difference. My buddy corrected me, saying that .308 is not available in heavier bullet weights and that .308 barrels are not cut with rifling that will stabilize heavier bullets. Is this correct? I only have a 30-06 and have not loaded heavier bullets than 180 Gr. so have never looked into it.

 

[Levi Garrett]

most 308 are 10 twist in stores as are 30-06 guns, which will work with the heavy stuff. I have a 13 twist 4 groove that has no problem with 150-168 . A tgt / varmint/ long range medium game setup which is what I wanted.
I have seen 12 twist more and more often , guess to get away from the one gun deal . This was an important factor, more so anyway than now . Times were tough not to long ago, and one gun was the norm for big game..
Limiting factor in .308 is you gotta have room for powder eh!

 

[p210sig]

A faster rifle twist like 1 in 10 even 1 in 12 will give you better stability & accuracy for heavier bullets in 180 Gr & 190 Gr for 308 wincherter. 30-06 has the nod for heavier bullets going to 220 Gr for shooting moose.

 

[TimberPig]

Many .308's are 1 in 12" twist rifling. Most .30-06's are 1 in 10" twist.

The .30-06 is thus better able to stabilize bullets of greater than 180 grains. The .308 is better with lighter weights.

The .30-06 also has greater powder capacity, and is thus a better choice if you want to shoot 180 grain or heavier bullets, as it can move them faster.

Practically speaking, good 165-168 grain premium bullets loaded in either will flatten any moose you shoot with it, providing you hit it in a vital area. 180's will also work well in either cartridge. The heavyweight bullets are not necessary to kill moose.

 

[Leeper]

The traditional twist for the 30/06 is the 1 in 10. It has been so from the beginning. This is probably because the initial 30/03 loading was with a 220 round nose bullet and the 30/40 Krag used the 1 in 10 twist so the designers saw no reason to change. Even when the 30/06 bullet was changed, the faster twist still worked.
The 308 (or 7.62) was designed from the start to fire the 147 to 150 grain bullet so a 12 inch twist was chosen. This twist is sufficiently fast to work fine with the 173 grain bullets (such as loaded in the Lake City Match ammo) as well. In fact, a twelve twist will stabilize bullets up to 200 grains if the bullet is a spitzer and to 220 grains if a roundnose.
Most factory 308's use a ten twist barrel. Probably just because all the other 30 calibers use that twist.
So most 308 Winchester rifles, regardless of make, will handle any bullet weights commonly available just as will the 30/06.
Loaded to similar pressures, the 308 will drive bullets of the same weight about 150-200 fps slower than will a 30/06. So a 308 will drive 150's to about 2850 while the 06 will drive the same bullet at 3000fps. 180's will do about 2600 and 2800 from the 308 and 30/06 respectively. An '06 will drive 220's to2550 while the 308 will manage about 2375.
The 308 will work very well with conventionally designed bullets in all weights including the 220's. Monometal bullets (like the TSX) work better at lighter weights driven faster. The 150 TSX at 2850 fps might be the ultimate 308 loading. The 130 at 3000+ might be even better on deer sized game. Regards, Bill.

 

[H4831]

TimberPig, I was just going to write this quote of yours-----Many .308's are 1 in 12" twist rifling. Most .30-06's are 1 in 10" twist.
------------
Your statement of lighter bullets shooting better in the slower twist 308s, is good theory.
However, in years past, this theory was hashed over more than any other subject I can think of. All the international gun writers took it up, but Jack O'Connor was quite vocal that a 30-06 would shoot 150 grain bullets just as accurately as would a 308.
When bench rest shooters more or less adopted the 308, this was looked on by some, and widely stated, that a 308 was more accurate than a 30-06. However, what I heard was since bench rest shooters load their ammo full power, sometimes plus, they used the 308 because of a bit less recoil, but considered the 30-06 just as accurate.

 

[brotherjack]

It depends on the length of the bullet. A 308 with the slower twist (1:12, which is the most common, even though many 308's are 1:10 or 1:11 (Savage, Tikka, and some others) - a 1:12 twist will indeed stabilize some very heavy bullets - the 220 grain Hornady Round Nose, for instance, will stabilize fine in a 1:12 twist (ask me how I know!).

I have personally never found a bullet that my 1:12 twist 308's won't stabilize, though on paper, some of the heavy boattail designs are probably too long and would cause problems (240MK's anyone?).

If you need a bigger/heavier bullet than a typical 180 grain hunting bullet, then you probably need a bigger gun than either a 308 or a 30-06.

 

[kombayotch]

You can buy heavy 308 hunting loads. How about a 200 gr. Accubond at 2550 fps. :

http://www.doubletapammo.com/php/ca...d=206&osCsid=ecd2e7fbde0df18ee1a51a6cb3908c7c

There are guys who have built 308s with 1-9" twist barrels and very long throats who are launching 208/210 gr. bullets at 2700 fps. and above. However, case capacity will always win out as far as velocity goes. Whatever you can do with the 308, you will always be able to top with the 30-06.

 

[Ganderite]

This is like a 30-30 vs 32Spl debate.

Savage and some other make the 308 with 1:10, so it will stabalize the same bullets as a 30-06.

The fact is that 308 is a short action, 30-06 is a long. Buy whichveer rifle suits the shooter. The moose cannot tell the difference.

 

[blargon]

All Sako and Tikka .30 cal rifles use a 1:11 twist. .308, .30-06, .300WSM, and .300WM. Fast or slow, you can use all bullet weights in any of them.

 

[TimberPig]

TimberPig, I was just going to write this quote of yours-----Many .308's are 1 in 12" twist rifling. Most .30-06's are 1 in 10" twist.
------------
Your statement of lighter bullets shooting better in the slower twist 308s, is good theory.
However, in years past, this theory was hashed over more than any other subject I can think of. All the international gun writers took it up, but Jack O'Connor was quite vocal that a 30-06 would shoot 150 grain bullets just as accurately as would a 308.
When bench rest shooters more or less adopted the 308, this was looked on by some, and widely stated, that a 308 was more accurate than a 30-06. However, what I heard was since bench rest shooters load their ammo full power, sometimes plus, they used the 308 because of a bit less recoil, but considered the 30-06 just as accurate.

You can then get into the theory that the shorter powder column, and shorter "stiffer" action make the .308 more accurate as well. There's a lot more to it than twist rate. By theory, 1 in 12" twist is better suited to lighter bullets than heavier, it doesn't mean light bullets won't be accurate out of a 1 in 10" twist. It may mean the 1 in 12" won't stabilize heavier bullets as well as a 1 in 10" twist, and this could affect accuracy with these loads.

As we both know, there are far too many variables in rifle accuracy, that any one factor is unlikely to be the sole cause of how accurately a rifle shoots.

In this case, the lower powder capacity reduces velocity of the .308 to levels that most shooters think is too slow, if bullets of greater than 180 grains are loaded. They may still think the '06 with its larger powder capacity is able to push them fast enough, while others figure a .300 magnum is needed for bullets of 200 gr plus.

In hunting rifles, the accuracy difference between the .308 and .30-06 is going to be negligible. The accuracy potential of the rifle and how the rifle likes the load is going to mean more than the theoretical differences in the potential accuracy of the round chambered. Most shooters, particularly hunters who are not gun nuts and into shooting will never be able to shoot well enough to tell the difference, nor do they care.