'06 vs 08 accuracy

[rodwhaincamo]

Heard that cartridges chambered in 308 cases are inherently more accurate than those of the same caliber in 30-06 cases. Does anyone know to what extent? Figure this may have to do with a more efficient case design. A flatter trajectory can be achieved with an '06 case. But out to 300 yds does this really matter? And are we talking about just 1/4 inch tighter groups?

[pilothunter]

The difference in accuracy between the .308 and 30/06 is really a moot point IMO. The variances between individual rifles would likely lead to a bigger difference in their accuracy that the "caliber" itself. The .308 does recoil less in like rifles, but not a big difference there either.

A short action caliber, such as the .308, might be theoretically a stiffer action, but, again variances in individual actions, barrels, barrel attachment, etc., would have just as much influence on overall accuracy. If one chose the .308 because it has been used more successfully in competition than the '06, sounds great to me. But in the real world and accuracy in a typical sporting rifle, it's simply a toss-up, I believe.

[moosemike]

Not with my .308. I picked up a Savage 110 .308 last summer. The best it would do was three inches with any loading I bought. I didn't reload for it because I frankly wasn't that interested in the cartridge and sold it. I know it is an accurate cartridge but not in that Savage. The '06 has always performed well for me.

[mavracer]

The variances between individual rifles would likely lead to a bigger difference in their accuracy that the "caliber" itself.

more than likely +1

[thinkingman]

some would say the shorter powder column results in more consistent burn, resulting in improved accuracy.
Conventional wisdom is the 08 is more accurate than the 06.

[taylorce1]

some would say the shorter powder column results in more consistent burn, resulting in improved accuracy.
Conventional wisdom is the 08 is more accurate than the 06.

I think that does have something to do with it as well, but with todays powders the deviations in velocity are pretty small. Better powders and primers help with this. Some say the shorter action is stiffer and that allows it to be more accurate as well. However for most people they will never be able to tell the difference in the two.

[handlerer]

I don't believe that either is intrinsically more accurate than the other cartridge. The 30-06 has a longer case neck allowing superior bullet bore alignment and the loading of the longer VLD bullets w/o intruding into case and restricting case capacity. The 308 is shorter, more powder efficient, always popular with large volume target shooters. More target rifles are chambered for 308, so many shooters associate that with being more accurate. For extreme long range accuracy the 30-06 is superior, because of the ability to load the heaviest target bullets. I have always thought that the short case neck on the 308 was a minor shortcoming, but is indicative of Winchester design philosophy.

[davlandrum]

My opinion is the "convential wisdom" is based more on the military/LE using it, which leads to some people thinking it is more accurate, then other people show up to the range and it looks like .308 is what every one else is using. If everyone is using it, it must be better...

Rather than the fact that the military wanted a 30-06 in a short action...

[JagFarlane]

The difference in accuracy between the .308 and 30/06 is really a moot point IMO. The variances between individual rifles would likely lead to a bigger difference in their accuracy that the "caliber" itself. The .308 does recoil less in like rifles, but not a big difference there either.

+1 there.

From what I understand, the .308 was designed using the .300 Savage, which was designed using the 30/06.

[moosemike]

The gov't wanted something to feed through the .30 machine guns at a higher rate of fire than the '06. The .300 Savage was tried but the sharp shoulder and short neck caused feeding problems. They (Winchester)developed the .308 and it filled the bill nicely.

[Slamfire]

If you have access to 1960's copies of the American Rifleman, in the Camp Perry issue are 300-600 round targets at 600 yards (or so) of that year's DCM match ammo.

At the time the velocity of the 30-06 load was 2650 fps with a 174 FMJBT, and the 308 was 2550 fps with a 174 FMJBT.

The powders used in the 308 and 30-06 were IMR 4895. The Army bought lots that were not blended, so the burn rate is always a little different that what is available to us, but the 30-06 load was around 47.0 grains. The bullet used in both cartridges was the old 174 FMJ. That bullet was the best you had, but the weight varience was plus or minus two grains.

The 308 target alway had a much tighter grouping than the 30-06.

The main difference between the cartridges was the air space. Forty seven grains of IMR 4895 does not fill a 30-06 case. I suspect that air space makes a difference in consistancy.

I have loaded thousands, maybe tens of thousands of rounds in the 30-06 with that load. It shoots very well. You can shoot cleans out to 600 yards with 47.0 grains IMR 4895 and a 175 SMK.

I also shot a lot of rounds with 55.0 grs IMR 4350 with 168's and 175's. That powder removed most of the air space in a 30-06 and that was an accurate load.

I will never see a 600 round target at 600 yards with a case filling powder in the 30-06, it would be interesting to know if removing the air space tightens the group.

It is hard to prove that in the hands of a shooter, at long range, that there is any real difference between the cartridges. Aiming error, positional error, and just bad luck on your wind call will move the bullet more (distance in feet!) than whatever theorical difference in accuracy between the 30-06 and the 308.

The basic reason the 30-06 disappeared from the firing line was the M1a. The civilian version of the M14 appeared in the 70's, and the 30-06 Garands are just harder to shoot well. Garands lose their tune sooner and they kick more. In a bolt rifle, the bolt throw is shorter, and that allows you to move less when you are wrapped up in a sling and working the bolt for ten shot strings of rapid fire.

The 30-06 really shines at long range when you start using 190's or 200 grain match bullets. You can push the things at the low end of the 300 WM, and the rifle will shoot them well.

[Gewehr98]

Buy me a pair of Nesika Bay actions, your choice of Krieger/Obermeyer/Shilen/Hart/Lilja barrels, match reamers, and the remaining bits, and I'll build a pair of precision rifles - one in .308, the other in .30-06. Feed them quality handloads, and I guarantee neither will be more accurate than the other. IOW, they'll each shoot tight groups, but the difference in group size will be a function of the guy behind the trigger, not the chambering.

[Jimro]

If you handload and are happy with sub MOA groups then either round will do you. Standard m118lr shoots tight a long way out there, hell it has more energy remaining at 1000 yards than a 40 caliber handgun at point blank range.

However, once you start pushing those 190 gr SMK's out of a 30-06, you get a few hundred more meters of ballistic advantage on the far end of the arc.

My target rifle is in 308 simply because they are readily available. But I wouldn't turn down an older Savage 110 Tactical in 30-06, sounds like a lot of fun to me.

Jimro

[Buzzcook]

The .308 was designed to have the same performance characteristics as the .30-06, in a smaller package.
The only real difference is that the larger case of the .30-06 will handle larger bullets and more powder. The extra powder capacity only helps in longer barrels.

As several people have said it's the rifle and the shooter that make the difference.

[Bart B.]

A friend of mine was the first person to shoot the .308 Win. in high power competition at the 1963 Nationals when it was first allowed. He won the Nationals by a handy margin and repeated it a few more times the next several years. The most accurate .30-06 bolt action match rifles at the time would hold about 5 to 6 inches at 600 yards. .308's would shoot about half that. The accuracy .308's had over the .30-06 caused so many unbreakable ties for the next three years, the NRA had to reduce the scoring ring sizes on targets to separate the outstanding scores from the excellent ones.

Meanwhile, the USN Small Arms Match Conditioning Unit got a batch of 7.62 NATO chambered 1:12 twist Garand barrels from the government's Springfield Armory then put them in a series of match conditioned M1's. Accuracy was about half of what the best 30-06 Garands produced. These Garands (also used by the USAF) shot more accurate than the other services M14NM rifles; it took the other services a few years to catch up. By the 1970's, both M1 and M14NM match versions would shoot inside 4 inches at 600 yards from accuracy cradles. The best 30 caliber Garands any of the services could build held about 8 inches at 600 yards.

Lake City Arsenal, after developing match ammo for this new round immediately noted M118 7.62 NATO stuff shot better than M72 30 caliber match ammo. Sierra Bullets used to use the .300 Savage case to test their 30 caliber bullets until the .308 Win. came out; they switched.

.308 Win. ammo from match rifles made with Win. 70 actions have shot smaller groups testing rifles and ammo at 600 yards smaller than most bench rest records at that range; .75 to 1.5 inch 10-shot groups for example. No .30-06 bullets from any barrel has even come close. Given a choice between either cartridge when both were allowed in US Palma rifles for 800 to 1000 yard matches, the best shots always chose the .308 as it was the most accurate and had less vertical shot stringing.

And though Winchester got the first contract to make thousands of 7.62 NATO ammo and commercialized the round as the .308 Win., they didn't develop it. Remington's Mike Walker (benchrest champ, designer of the .222 Rem.) headed the team of folks modifying the .300 Savage case to withstand full auto cycling. I believe they were working with Frankfort Arsenal in this cartridge development.

Bullets as heavy as 250 grains have been shot from .308's winning 1000 yard matches doing so. Not too shabby for exiting the 1:8 twist barrel at only 2150 fps.

Most of the accuracy difference between these cartridges was caused by the leade angle in the chamber's throat; 2.5 degrees for the .30-06 but only 1.5 degrees for the .308. The .308's shorter powder charge helped as well as more shoulder area and sharper angle reduced shoulder set back when the firing pin slammed the case forward in the chamber resulting in more uniform primer detonation. A .30-06 with a 1.5 degree leade angle and ammo with uniform muzzle velocity may shoot as accurate nowadays as a .308. But the milder recoil during barrel time a .308 has makes it easier to shoot accurately.

[T. O'Heir]

"...308 cases are inherently more accurate..." Has to do with the short 'fat' case to bullet diameter ratio vs a long 'thinner' case to bullet diameter ratio. There's a long and involved scientific explanation on-line some place. Don't ask me where though. Saw it several years ago.
Been telling every female I know that short and fat is better, for eons. They don't seem to believe being built for comfort matters either. snicker.

[Bart B.]

Gewehr98, build just a .30-06, then test it at 600 yards shooting 40 consecutive shots fired about 30 seconds apart. If they all go inside 2 inches, then you've done it and I'll applaud you for your success. This is an example of what a .308 built on a pre-'64 Win. 70 action's done with full length sized cases in a SAAMI spec chamber. You can get one of these for a lot less than a Nesika Bay action.

handlerer, a chambered rimless bottleneck round's alignment with the bore when fired is controlled by the case shoulder centering in the chamber shoulder. These two coned sufaces meet and center on each other when the firing pin drives the case forward. If the case neck's not well aligned with the case shoulder, the bullet won't be aligned with the bore. Neck length has nothing to do with it. Case necks don't touch any part of the barrel with its few thousandths clearance to the chamber neck. And best accuracy is typically made with the bullet touching the lands to help center it in the rifling before its fired. Of course, the back end of the chambered case is off center being pushed there by the extractor, but the tiny angle the case has off the chamber axis doesn't matter.

[Regolith]

I wonder how many people who think the .30-06's longer case makes it less accurate thinks the same of the .300 Winchester magnum (which the military has started moving towards in lieu of the .308 win because it performs better at longer ranges)?

The .300 Winchester Magnum is 8mm longer in length than the .30-06. If the length of the powder column effected accuracy at all, this longer cartridge would not perform as well at long range as either the .30-06 or the .308. However, there are many .300 Winchester magnum rifles out there that perform to 1 moa or better at 1000 yards, many of them in the hands of the military.

Simply put, it's the rifle, not the cartridge. After the .308 came out, all of the newer precision rifles were built in that cartridge, where as relatively few were built in .30-06. This is most likely the cause of this myth - all the newer advances in rifle design were applied to .308 rifles more often than .30-06 rifles, leaving some with the impression that it was the cartridge that mattered, and not all the new technology that went into the rifles.

If anything, the .30-06 may enjoy an advantage in accuracy over the .308 because it can handle longer, heavier bullets which have a higher ballistic coefficient, and hence work better at longer ranges. It also has a larger powder charge to push those bullets at a higher velocity, flattening out the trajectory.

[Art Eatman]

Probably, the higher velocity when out in Ma Bell country means that the bullet goes farther before transitioning down to subsonic. Probably more important than the trajectory?

Once the .308 came into use, that's where the R&D went for platforms and, of course, loads. Makes a difference.

Shifting emphasis: If "short & fat" is better than "long & thin", then the next progression oughta be the .300 WSM, right? Think R&D.

[Bart B.]

Regolith mentions:

After the .308 came out, all of the newer precision rifles were built in that cartridge, where as relatively few were built in .30-06.

I disagree. So do thousands of folks who continued to use their .30-06 rifles in competition up to 1000 yards for 8 years after the .308 was allowed. Both cartridges used the same barrels made to equal bore quality (Hart, button rifled then lapped to spec by Al Hauser), but these folks insisted they would equal or better the .308 with that 50 year old cartridge.

Well, they didn't. I've shot many matches with those who refused to admit their .30-06 rifles built to the same standards as .308's were didn't shoot as accurate. After the NRA reduced the scoring ring size on 1000 yard targets in 1971 (8 years after the .308 was allowed), they were convinced and eventually changed over. The typical response from those good shots who changed was both sheer amazement and complete satisfaction. Finally, they had learned what the top 10 percent of the competitors had known since 1963.

Some folks today don't believe this, but historical facts remain as they are.

Few, if any rifles made today, benchrest or whatever, have equalled what test groups from NRA match rifles produced.

Regarding:

I wonder how many people who think the .30-06's longer case makes it less accurate thinks the same of the .300 Winchester magnum (which the military has started moving towards in lieu of the .308 win because it performs better at longer ranges)?

The reason the military shifted to the .300 is two fold.

First, the military wanted a round that bucked the wind better than the .308 at long range.

Second, from the 1960's through the 1970's, the .30-.338 cartridge was the favorite for long range matches. Its modified case (belt and rim turned down to body diameter) was being considered as the standard sniper round for SEAL teams, but the expense of making cases and having a non-standard readily available one wasn't wanted. .300 Win. Mags became more often seen used by military teams as they didn't want to expense sizing .338 Win. Mag cases down to 30 caliber. Although a bit less accurate than the .30-.338, the .300 did well and the accuracy difference is small enough to not make any tactical difference.

[Sarge]

My advice is to find a Savage 110 in whichever caliber suits you the best, and build out from there. If it's like any of the 110's I 've owned, shot and tweaked over the years you probably won't have much 'building' to do.

I'm firmly in the camp that says the rifle is the biggest component in the equation.

[44 AMP]

But this dead horse only gets up and trots for the benchrest/match shooting crowd. And even then, it doesn't gallop.

For ordinary hunters and shooters, either caliber is accuracte, if the individual rifle being used is. And any individual .30-06 may out shoot any individual .308. Just as any individual .308 may out shoot any individual .30-06.

Taken in large enough numbers (hundreds or thousands of rifles), there may be some basis to say the .308 is inherenetly more accurate. But the difference isn't alot. Important enough to the guys who are looking to win matches, but not so much for the rest of us.

Decades ago, conventional wisdom was that the M14 was the most accurate service rifle. And it was generally true. RACK grade M14s generally outshot rack grade M1s and even 1903s. With tuned target guns, not so much.

When it comes to civilian sporting rifles, the type and class of the rifle you have will have more of an impact on your accuracy than the choice of chambering in .30-06 or .308 Win.

[Bart B.]

44 Amp says:

Decades ago, conventional wisdom was that the M14 was the most accurate service rifle.

Not until the Army and Marine Corps 'smiths learned how to make them shoot 7.62 NATO ammo as accurate as the USN and USAF Garands rebarreled in the early 1960's to this new round. The best of these match M1's would hold 4 inches at 600 yards. It took the other two services a few years to catch up, but they finally did. Few people know how very accurate these rifles were. Especially because of all the moving parts that had to go back to the same position with the same pressure for each shot.