Can we revisit the 308 vs. the 3-06 one more time? I swear it is a good question

A

ahenry

New member
Ok I have different slant on the never-ending .308 vs. 30-06. *grin*
I have always wondered why bench rest shooters have preferred the 308 over the 30-06. I have done a lot of looking into the ballistic differences and it seems to me that the –06 is superior. I keep hearing that the “shorter fatter” caliber is more accurate but for the life of me I can’t find anything to actually back that up. The best I can get in that arena is “Well Joe Blow knows his rounds and he tells me that the 308 is more accurate....” or “All the 1000 yard matches are won with 308 rather than 30-06.”. All this might be true but I am trying to get to the real reason. The best think I have come across so far was from a friend of mine. He said that given that one round is just as accurate as the other (I tend to think this is correct) most people prefer the lighter recoil of the 308 as opposed to the –06. This makes good sense to me. Is this really the only reason a 308 is the caliber of choice for bench rest shooting?

This also leads me into another question. I have only shot a 30-06 once and that was several years ago, but I don’t recall the recoil as being anything real rough. It certainly kicked but I didn’t even consider it to be different than my Dads 300 Sav. or other 308’s. For those of you that have more –06 experience was I just ignoring it or is the recoil really about the same?
 
All I've ever shot are hunting rifles and military rifles in these cartridges. I've never owned a heavy-barrelled target-variety .308 or .30-'06, although I've shot both cartridges in sporters and reload for both.

In a sporter, I can't tell any difference as to accuracy.

From the standpoint of impact damage on a steel-plate target, the .30-'06 handloads "do more hurt".

Any difference in recoil is negligible.

FWIW, Art
 
The short squat cartriges supposedly burn more consistently so the 308 is more accurate. However the next best super accuracy long range cartrige is considered by many to be the 300 Winchester magnum which is neither short nor squat, and even has a belt which supposedly hurts accuracy.

I tend too think that the most accurate cartridge is the one that has had the best load development. Lot's of folks and manufaacturers working on the 308 for 40 years while the 06 has remained pretty static in that time frame.

Just my guess, Blue Duck
 
I prefer the 308 as a military cartridge because it duplicates the ballistics of the military loaded 30/06 in a shorter, more efficient case.
I prefer the 30/06 as a sporting cartridge because the larger case is more versitile and can be made to handle the same bullet at a higher velocity.
In any case, the quality of the rifle is more important than any difference between these two cartridges.
I suppose that if one were building the all out competative rifle for some sort of long range shooting, one would want to go with the 308 just to strike out that question of the shorter case making some sort of difference in accuracy through increased consistancy of ignition, but I would have doubts of this being of any tangible advantage in a fine rifle made for either military or sporting use.
 
.308 vs. .30-06

The 308 has the advantage of having a higher max pressure than the -06. It's only about 2000 psi though. Negligable when you are talking about 52000psi for the 308. The reduced powder capacity of the 308 makes it easier for the handloader to load the case to max capacity which has been known to improve accuracy, although not necessarily in all cases. When loaded to max pressure the 308 will equal the -06 with bullets under 150 grains. But when you get into the bullets that are much heavier such as the 180, 185, 190 etc... then the -06 has the advantage of the larger case capactity, and the ability to hold larger amounts of the slow burning powder to push the heavy bullet down the barrel.

Branden
 
Tad bit more....

Interesting points.

Art thanks for the info on recoil it was as I sort of suspected.

Blue Duck, I had heard this about the “short squatty” cartridge but I can’t find anything to support it. Do you have something you could toss my way? I like your point about the load development. That could certainly explain it. However, if each gun requires a little bit of a “personal” load (I have never done any bench rest competitions so this is really “so I’ve been told” information) wouldn’t an –06 require just as much time as the 308 in developing your particular guns’ load? Just thinking out loud here, not really sure at all...

Herodotus, Why do you think it is better to have the more “efficient” round? I don’t understand what makes a round that spits out the bullet quicker superior to one that builds a bit more pressure before it spits out the bullet. I would ass-u-me that if there were an advantage there it would explain why bench shooters prefer the 308. I just can’t come up with a reason why that is better....
I like the 30-06 for the very reason you say; it is more versatile. To me that implies a better caliber though, no? Better in Bench rest comps, hunting, sniping, plinking, ad infinitum...
I couldn’t agree with you more about the quality of the rifle being more important than the caliber. What if we are talking about two of the same rifles, like Rem 700’s? In this situation the quality and fit and “other” factors are exactly the same. I think that is close to what you would find in a bench rest competition. The great majority of the rifles used are probably custom made and fit to the shooter. If they are building “THE target rifle” why choose a caliber that appears to be inferior?
You mention “increased consistency of ignition” in regards to the shorter round. Can you elaborate? How does this improve accuracy? Does it allow more consistent pressure build up? Like I was saying it doesn’t all make sense. Not to say it isn’t true, but I could use some help in understanding why....
 
Bandenburkhart, I just missed your post...

Let me see if I understand what you are saying. The greatest accuracy (in general?) is when a cartridge is loaded to max capacity. Therefore you reach that capacity sooner (with less pressure build up?) in a 308. Is that right? How does that help? I guess I see what you are saying but I am not familiar enough with ballistics to understand the benefits gained. When you say “easier for the handloader” do you mean that it takes less effort to fill the case with powder or less trial and error to develop the load?
It also seems like you are saying that a 308 loaded to max capacity (greatest accuracy?) is equivalent to –06 ballistics. If it is just the equivalent of, why doesn’t everybody go with the –06? Seem to me that a shooter would be better off with the largest range of bullet selection. This would seem to allow him the greatest versatility in picking a bullet size that works best with his particular gun.
 
Here's the definitive post from rec.guns, by Bart Bobbit

".... I'm talking about NRA match rifles; bolt action ones that shoot more accurate than service rifles. The only change made was the chambering reamer used and a shorter magazine was used. Stock, action, barrel and sight quality were still the same. But the .308 Winchesters shot much smaller groups than the same rifles with .30-06 barrels.

At the time (early to mid 1960s), the M14 match conditioning processes were not up to what the best M1 rifles were capable of. M1s in 7.62mm NATO were the best, most accurate service rifles made. The good ones would shoot into 4 inches at 600 yards. But none of the .30-06 rifles of any action type would do that well.

Someone posted comments that 200-gr. bullets were the max for a .308. He should have seen one of our national champions shooting 250-gr. Sierras from his .308 Win. Palma rifle at 1000 yards. Although the bullets left at only about 2150 fps, they shot as accurate as folks using 190s and bucked the wind a bit better. He had to use a 1:8 twist with a longer throat to do it, but it sure worked well. With a 1:10 twist, 220-gr. bullets can be shot very accurately from a .308 Win; I've done it myself. Groups at 1000 yards were about 8 inches for 20 shots.

Yes, a .30-06 will shoot a given bullet weight faster than a .308 and will have less wind deflection. But the improved accuracy of the .308 will print a smaller group with a +/- 1 MPH wind effect due to the smaller groups it shoots. The increased wind bucking the .30-06 has is about 4%, but top shooters prefer groups 60% smaller which easily makes up for the wind bucking differences."

"Both the .308 Win. and .300 Win. Mag. tend to be more accurate than the .30-06. Both win a lot of 1000-yard highpower matches while the 30-06 seldom does any more if at all."

"Lets go back to when the .30-06 and .308 were the only cartridges allowed in NRA match rifle matches. Both cartridges were used in barrels of equal quality as well as the same action and stocks by several top shooters in the USA. Both cartridges were used in matches at ranges from 100 through 1000 yards. Many thousands of rounds were fired in both types. Bullets from 168 through 200 grains
were used with several powder, case and primer combinations.

In comparing accuracy between the .308 and .30-06, folks who used each quickly agreed on one thing: .308s were two to three times more accurate than the .30-06. In the early 1960s, it was also observed that competitors with lower classifications using .308s were getting higher scores than higher classified folks using .30-06s; at all
ranges. By the middle to late 1960s, all the top highpower shooters and virtually all the rest had switched to the .308. The Highpower Committee had received so many complaints of ties not being able to be broke between shooters using the .308 and shooting all their shots in the tie-breaking V-ring, something had to be done to resolve this issue. In 1966, the NRA cut in half the target scoring ring dimensions.

At the peak of the .30-06's use as a competition cartridge, the most accurate rifles using it would shoot groups at 200 yards of about 2 inches, at 300 of about 3 inches. 600 yard groups were 6 to 7 inches and at 1000 yards about 16 inches. As the high-scoring ring in targets was 3 inches at 200 and 300 yards, 12 inches at 600 and 20 inches at 1000, the top scores fired would have 90+ percent of the shots inside this V-ring.

Along came the 7.62mm NATO and its commercial version; the .308 Win. In the best rifles, 200 yard groups were about 3/4ths inch, at 300 about 1-1/2 inch. At 600 yards, groups were about 2-1/2 inch and at 1000 about 7 to 8 inches. It was not very long before the .30-06 round no longer won matches nor set any records; all it's records were broken by the .308 by a considerable margin. Some accuracy tests at 600 yards with the .308 produced test groups in the 1 to 2 inch range.These were 20 to 40 shot groups. No .30-06 has ever come close to shooting that well.

At 1000 yards, where both the .30-06 and .308 were allowed in Palma matches, the .308 was the clear-cut most accurate of the two. If top shooters felt the .30-06 was a more accurate round, they would have used it - they didn't. In fact by the early 1970s, the scoring ring dimensions on the 800 - 1000 yard target were also cut in about half due to the accuracy of both the .308 Win. over the .30-06 and the 30-.338 over the .300 H&H when used in long range matches.

Most top highpower shooters feel the main reason the .308 is much more accurate than the .30-06 is its shorter, fatter case promotes more uniform and gentle push on the bullet due to a higher loading density (less air space) and a more easily uniformly ignitable powder charge.

Military arsenals who produced match and service ammo in both 7.62mm and 30 caliber have fired thousands of test rounds/groups with both. They also found out that with both ammo types, the smallest groups were with the 7.62 by about 50 to 60 percent. M1 rifles in 7.62 shot about twice as small of groups as .30 M1s at all ranges. When the M14
was first used, there were some .30-06 M1 rifles that would shoot more accurately. It took the service teams several years to perfect the methods of making M14s shoot well, but when they did, they shot as good as M1s in 7.62.

There will always be folks who claim the .30-06 is a more accurate cartridge. All I have to say to them is to properly test .308 vs. 30-06 and find out. Theory is nice to think about; facts determine the truth." Bart Bobbit
 
Smitz, I don’t want to nitpick your article so let me just say this. I have read things like this all over the place and I don’t buy it. It is really nothing more than some guy saying that back in the ‘60’s 308’s out performed 30-06’s. I could mention several reasons why I don’t buy some dude saying this without anything to back it up (it would probably mean more if I knew who Bart Bobbit was...). I am not saying he is wrong (or by extension you) just that there is nothing to support it that I can find. Matches won with a 308 in modern matches don’t compare because nobody shoots the 30-06. He talks about how it took a few years to get the quality of the M14 up to par with the M1. That could also mean that while lots of work was being done to improve the accuracy of the common match rifle chambered for the 308, the M14, (obviously Winchester had lots of reason to work on this round) very little work was done on the M1. Basically leaving it in the dust of technological advancement. He does mention one little blurb about the higher density of the 308. As I said before I am a bit lost as to why that is so great but I will try to do a little cogitation on it and see what I can think of (any help here would be great...). If the higher density does improve accuracy I would suspect that this would be an across the board improvement. Meaning that any caliber loaded to max capacity will be more accurate than the same round loaded with less powder. Sounds like what you were saying brandenburkhart. I am still pretty new to hand loading so I don’t have any personal experience to support one claim or the other, but I would think that in order to have a good test the lighter load would have to have a lighter bullet (that way there is a true test of how the burn rate affects things, not how a light load struggles more to push along the heavier bullet...?) Does anybody have something that I could look at along these lines?

I guess one of the reasons I doubt the superiority of the 308 to the 30-06 is because in all other rounds when looking at ballistic differences between two calibers the faster, more versatile, and heavier bullet moving at the same velocities as a lighter bullet in the other caliber round is considered superior (boy, read that sentence again *grin*). I have no real desire for one to be better than the other, in fact I don’t own a rifle in either caliber. That lack in my collection was what sparked this whole line of thinking in the first place.

I am certainly enjoying all the great thoughts though....
 
One aspect of the .308's accuracy potential is due to the loading density afforded by the smaller case capacity. It isn't so much reaching higher pressures faster or anything along those lines but more to do with a consistant uniformity.

THE key to shooting everything into the same hole is to have everything the same shot-to-shot. In many instances, the .30-06 won't allow a completely full case (100% loading density) which leads to the powder being at various (inconsistant) levels/attitudes in the case. I'd suspect that any suitable powder for any given caliber/cartridge that is right at a compressed load (or just above) would have a better chance for uniformity, hence accuracy - all else being equal (that's a WAG but based on some experience).

Beats me about the .300 - zip for personal experience w/that one & who needs the pounding anyway? ;)

One aspect of THE most accurate catridges is a short, fat case AND with a very sharp shoulder angle (the PPC-series which have taken over the bench rest records come to mind).

JD Jones/SSK (of TC Contender wildcat fame) bases many of his offspring on a .444 Marlin parent case, blown out straight with a VERY sharp shoulder. I've one in a .309 JDJ 14" bbl Contender which approximates a .308 Win in a
18-20" bbl rifle & is one of the most accurate firearms I have ever had the priv to shoot - easily boring (& frustrating!) in that it always does its thing - but only when I'm up to it.

R Jamison/Shooting Times also did a .300 J~ (165s at ~3000 fps) based on a .404 Jefferies (?) case which had the same trademark of a (relatively) short, fat case w/sharp shoulder. As I recall, when he did the load development, increasing powder charges by 1.0 gr increments still placed all bullets through the same (relative) hole = still right at MOA. Seems things would change w/velocity but it does indicate a high degree of uniformity there .... (as an aside, I do think I want one of those built up on a Rem M7 20" bbl ... another thread ... )

Whatever & I digress .... uniformity is the key & it appears that the .308 acheives that a bit better than does the .30-06 - all things considered.
 
ahenry,
I don't have a lot of match experience with centerfires but it is almost unversally accepted that .22s in the lower velocity offerings are much more accurate than their hotter counterparts.
 
I just have a hard time making the connection...

When you have the same two bullets, departing the muzzle at the same velocity, from the same barrel, using the same rate of twist, with the only difference being the case capacity and pressure rating of the cartridge that pushed said bullet to said velocity in said barrel. Granted, something can be said for the shorter cartridge (.308) allowing a shorter and stiffer bolt action, which lends itself to improved accuracy, but how would the exterior ballistics, and subsequent downrange accuracy, be any different once the bullet leaves the muzzle? And that's not just between the .308 and .30-06, you could throw in the other .30's of similar velocity, like the 7.5x55 Swiss, it's ballistic cousin the .30-284 wildcat (recently favored by the benchrest crowd), or even a downloaded .300 Magnum, all capable of pushing a .308" buulet out the muzzle at the same velocities as the others. Why would any one of them be more or less accurate, if the only variable was chamber dimensions? Is there some rule of physics that gets bent in favor of one over the other?
 
To all, I neither fully understand nor endorse Bart's write-up, but it's what is posted on rec.guns whenever the question comes up.

Gewehr98, I believe the assumption of yours that breaks is: departing the muzzle at the same velocity. The argument is based on the consistency of burn rate, which will affect the muzzle velocity. Shot-to-shot consistency is key.

-z
 
ahenry wrote: "Matches won with a 308 in modern matches don’t compare because nobody shoots the 30-06."

Isn't this fact alone telling enough? For me, it speaks volumes. If match shooters--here we're talking about people who invest thousands of dollars and countless hours of their lives--could win matches with the .30-06, why wouldn't more of them shoot this round today? I doubt seriously that it's merely because they've heard that the .308 is more accurate. We're talking about people who experiment at great lengths with equipment in order to achieve a miniscule improvement in accuracy. They don't simply take someone else's word for it; they put various calibers to the test. And simply, the .308 outperforms the .30-06 in competition. In this context, where shooters tweak equipment and loads with exacting precision, it's a more accurate round.

What does this mean for the average person buying off the rack? Nothing really. I doubt there's any advantage for the shooter who picks up a Remington 700 for deer hunting. Both rounds are more than accurate for this task. I actually chose the .308 here not so much because of inherent accuracy concerns, but because I could practice with milsurp ammo a lot cheaper with the .308. I don't reload yet.

This consideration, more than anything, is the one that will most improve my accuracy (and 99% of other shooters, I suspect). Practice, practice, practice.
 
Back in the early days of the .308, when there was less fear of tort liability and velocities and pressures were commonly printed on the ammo-box: The .308 was loaded to some 53,000 psi; the .30-'06 to around 49,000 psi--except for the 110-grain loadings.

I guess they figured that folks who bought 110-grain '06 ammo were not using old, tire military rifles. Dunno.

When you load the '06 to 53,000 psi, the muzzle velocity will be 200 to 300 ft/sec faster than a .308 of the same barrel length. Anybody wanna argue? Please; don't.

Now, where I'm coming from is that my own sporter '06, with its 26" barrel, regularly shoots three-shot groups of under one inch. My best is 1/2"; 3/4" is more common. I have two four-shot groups at 500 yards of four inches. I called two fliers out of a ten-shot string; the other eight were 6-1/2". That is more than accurate enough for the hunting I do.

A .308 Savage Scout, with a 150-grain military load, did not make a dent in my one-inch steel plate at 500 yards. My 150-grain handloads made a 1/16" dimple. My 180-grain SPBT handloads made a crater 3/16" deep, and 1/2" diameter.

Ergo, to wit and therefore, I will stay with my '06, thank you.

:), Art
 
For mere mortals, I agree with Art, the .30-06 is ballistically superior.

For those who are obsessed with absolute accuracy (consistency), .308 appears to have a slight edge over .30-06.

-z
 
With the caveat that I'm ignorant of technical issues
involved...

It would seem to me that there would have been something
of a bias against the .308 since it was newer than the
venerable .30-06 and military and/or gun folks seem
to be conservative and somewhat suspicious of change.
If that is true, ahenry's post would seem invalid.
Meaning that if folks don't shoot the .30-06 now, that
is because they all switched to .308...but since the
.30-06 was first (by alot I would guess in terms of
years), that was their second switch, and they had
made the first switch (away from the .30-06) since the
.308 was more accurate. So, there would have been
lots of effort put into the .30-06 before and during
the initial stages of the .308, and it still couldn't
keep up with the new-fangled .308.
I hope that makes sense...

Howard
 
Smithz, what's broken about my assumption? "Departing the muzzle at the same velocity" is exactly what I said. In other words, a 168gr Sierra MatchKing departing the muzzle at 2700fps doesn't know the difference between the .308 or .30-06 that got it there in the first place. If you're referring to shot-to-shot consistency, especially with respect to velocity, I'll agree wholeheartedly, accuracy does depend on it.

That's not saying, however, that one cannot load consistent, accurate .30-06 match loads, either. Far from it. While not a one-hole benchrest gun, my "new" 1903A4 restoration, with new 2-groove March 1944 Remington barrel, recently produced a 3/4", 5-shot 100 yard group. The load? 45.5gr of IMR4895, behind that 168gr Sierra MatchKing, lit by Federal 210 Match primers, and wrapped in Lake City '68 brass. I'd actually debated whether I would build it to chamber .308, just to make my handloading tasks easier between it, my M14NM, and Remington 700PSS. Then I thought about the folks who decided to pursue using that platform for sniping purposes, and I deferred to the original caliber. I doubt the gun would've shot any better had I chambered it for the shorter round.

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