.308 v. 30-06 Accuracy Issue

[4fingermick]

You see a lot of serious target guys shooting the 308, not many shooting the 3006. For hunting and military shooting, both great rounds, accuracy wise the 308 always gets the nod.

 

[OneShot!]

Hk 91 .308

I purchased HK 91 in .308 caliber. I must say I am very impressed by the weapon. Its a beautiful semi-automatic. I am sure with some excellant gun smithing it can be turned in selective fire.

 

[USSR]

Hey guys, let's leave rifles out of the discussion here. The question is simple. Which one is more accurate?


That means it would absolutely have to be some sort of characteristic of the cartridge itself. This has nothing to do with benchrest, highpower or any rifles or components other than the cartridges themselves.

DTOM,

A cartridge is a d@mn hunk of brass holding powder that when ignited, propels a bullet at a certain velocity. A .30 caliber bullet at 2700fps doesn't care what the cartridge case headstamp says, it's only concern is it's engagement with the bore, whether it entered the bore dead straight, whether the lands and grooves are the same from the throat to the muzzle, and whether the crown will allow the bullet to release itself from the bore evenly at the muzzle. Talking about a cartridge's "characteristic" is so miniscule that it takes you into the benchrest realm, which you yourself eliminated. You are simply debating how many angels can dance on the head of a pin when you eliminate the rifle and deal only with a brass case.

Don

 

[RubenZ]

Using Factory equipment I'd take my .270 instead Flatter shooting than both of those imo.

As for original question, my vote goes to the .308win

 

[Donzo]

Since I don't own anything in .308, I'd have to say the 30-06 is definately the most accurate in my collection.

 

[Don't Tread On Me]

A cartridge is a d@mn hunk of brass holding powder that when ignited, propels a bullet at a certain velocity. A .30 caliber bullet at 2700fps doesn't care what the cartridge case headstamp says, it's only concern is it's engagement with the bore, whether it entered the bore dead straight, whether the lands and grooves are the same from the throat to the muzzle, and whether the crown will allow the bullet to release itself from the bore evenly at the muzzle. Talking about a cartridge's "characteristic" is so miniscule that it takes you into the benchrest realm, which you yourself eliminated. You are simply debating how many angels can dance on the head of a pin when you eliminate the rifle and deal only with a brass case.

Don

Don, I understand that. All I'm wondering is if the length of the cartridge makes a difference. That would be a characteristic specific to the cartridge, not any platform using it. I assume all things are equal here. I suppose the only things that could possibly make a difference are the length of the powder column, and the angle of the shoulder. There are those (not me, just playing devil's advocate here) who say that a shorter/fatter cartridge is more accurate due to the more consistent pressure curve produced by the physical space in which the powder burns. This is what I've read and heard. Is it just nonsense to try and give credence to the whole shorty/fat cartridge fad these days? Maybe. I don't know. This isn't my area of expertise.


I just thought that the question being raised was between the cartridges themselves. I think you're right. It's splitting hairs. A professionally gunsmithed and tuned .30-06 with match-grade parts and top-notch handloading should be extremely accurate to where it doesn't really matter. That's what I think.

Is there a reason benchrest people use 6mm? Is there something about the proportions of the projectile in comparison to the case size and volume and shape which makes it more inherently accurate? If so, then can these factors apply to .308 vs. .30-06?

 

[USSR]

DTOM,

In theory, there are several factors regarding the case itself that come into play. As you mentioned, the length of the powder column and the angle of the shoulder are a couple. Also, a shorter cartridge can be used in a shorter receiver which may be stiffer than a longer one. As for the "...shorter/fatter cartridge is more accurate due to the more consistent pressure curve produced by the physical space in which the powder burns". This is only true if the powder and bullet used is optimized to the shorter case. For example, in the case of IMR4895 and the approximate 150gr bullets which were used in both USGI .30-06 and .308 ammo, the powder nearly filled the .308 case, while the .30-06 case had space between the top of the powder column and the base of the bullet. However, once you move to a heavier bullet and slower burning powders more suited to the .30-06's case capacity, then you have a situation where the .308 case cannot hold enough powder to propel the heavier bullet at a suitable velocity, and the .30-06 is likely to be more accurate. As for the 6mm bullet used in BR, this is a case where everything (case, bullet, powder column, primer size, etc.) have been optimized to produce the best results within an artificial environment (ie. the rules of the game). Also, unlike commercial cartridges which are chambered in thousands of factory rifles, some of which are of questionable quality and will exhibit questionable accuracy, the benchrest cartridges will always have a sterling reputation simply because they are only chambered in the highest quality custom built rifles. I think you nailed it when you said, "A professionally gunsmithed and tuned .30-06 with match-grade parts and top-notch handloading should be extremely accurate to where it doesn't really matter". Just make sure you optimize your load to the .30-06's case capacity, and don't try to duplicate a .308 load in the larger '06 case.

Don

 

[RubenZ]

Don you forgot to add in Bbl Twist

 

[USSR]

Don you forgot to add in Bbl Twist

Yes, indeed. Thanks RubenZ.

Don

 

[Slamfire]

“I just thought that the question being raised was between the cartridges themselves. I think you're right. It's splitting hairs. A professionally gunsmithed and tuned .30-06 with match-grade parts and top-notch handloading should be extremely accurate to where it doesn't really matter. That's what I think.”

The American Rifleman Magazine published 600 round groups with the NM match ammunition used in the 1960’s Nation Matches. Both cartridges, 308 and 30-06 used the 174 FMJ and IMR 4895 powder. The 308 groups had significantly less dispersion than the 30-06 groups. This is probably due to the air space in the 30-06. I have always been curious if 55 grains of IMR 4350 would have reduced the dispersion as there is very little air space left in the case when that load is used.

The 308 is basically obsolete for a target round, the accuracy is there, but shooters prefer the better ballistics of the 6 mm and 6.5 mm cartridges and the lesser recoil. Unfortunately the classic bolt gun is disappearing from the firing line. Back in the 70’s there were only a few “Top Dogs” who were shooting 30-06 in the bolt gun. Larry Moore was one of these and his short range load was a 168 SMK with 42.0 grains IMR4895. Still a great load at 200 yards. However most of the shooters were shooting 308, but it really was not an accuracy issue, it was more of a perceived accuracy issue (those lot acceptance data sheets). Then the availability of 308 brass was very good, there was the slightly reduced recoil of the 308, and the shorter bolt stroke of a 308. For those who have never shot rapid fire with a bolt, the longer the bolt throw, the more you break position. At the end of the day, a dropped point is a mile deep chasm.

I shot a 30-06 Match rifle for a couple of years, but when I shoot classic bolt rifle I am using a 308. I cannot say that with an unsupported rifle that there is any noticeable difference in target accuracy between the 30-06 and 308, so I guess that means I get to keep those cleans I shot with the 30-06.

 

[RubenZ]

I have a .244 that is a tack Driver! Too bad you cant find ammo for it anywhere. Gotta use 6mm.

 

[Gewehr98]

USSR nailed it on the head.

Like someone else already said -- ALL THINGS BEING EQUAL ...which one is more accurate?

All things being equal? Neither. Find a reputable precision rifle gunsmith to build two identical rifles, using top quality receivers, barrels, chambering reamers, brass, primers, bullets, and powder. Chamber one in .30-06, and one in .308.

At the end of the day, the better shooter pulling the trigger will prevail. The differences between the cartridges will be indistinguishable.

I noticed that after I got into OneShot's chili over his plethora of inane polls at TFL, he started to duplicate those activities here. I'm curious if he knows what the search function is all about, or he just enjoys posting the myriad AK vs. AR polls.

 

[Howard Roark]

Gewehr98 is correct. Both are equally accurate. As is most any other caliber capable of the range it is shot at. The fact is that a 30-06 will shoot any bullet weight faster due to the greater powder capacity of that case as opposed to a 308. This comes into play when shooting in the wind which is always blowing at some point in a match. There might not be any wind in the morning but there will be wind later in the day. The faster bullet between the two will have a higher BC and will be affected by the wind less.

 

[USSR]

I noticed that after I got into OneShot's chili over his plethora of inane polls at TFL, he started to duplicate those activities here. I'm curious if he knows what the search function is all about, or he just enjoys posting the myriad AK vs. AR polls.

Gewehr98,

I'd say you nailed it. He's got another inane poll going.

Don