Shouldn't a .30-06 have a 24" Barrel?


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Kestrel
November 24, 2003, 12:51 PM
I was wanting to find an older (pre-lockout device) 700 BDL in .30-06. Don't know why I never checked, but found out they have a 22" barrel. Shouldn't a .30-06 have a 24" barrel for optimum velocity?

Thanks,
Steve

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Omaha-BeenGlockin
November 24, 2003, 01:09 PM
I've been looking real hard at a Weatherby SBGM in .30-06 the dealer has a good deal on---it also has a .24in barrel. Weighs 5.75 LBS.

My line of thinking is that with the longer tube and high energy loads---I can approach the .300 Win mag---with the smaller standard action---less recoil and cost---with more available ammo---if need be out in the sticks----they always have .30-06 and .270 available----anything else and you take your chances.

I also have a 3x9x40 Zeiss Conquest laying around the would go on that Weatherby quite nicely----lol.

BusMaster007
November 24, 2003, 01:20 PM
My beloved little Remington 7400 Synthetic Carbine and its 18.5" bbl. shoot just fine. (edited to add: it's only available in .30-06)
Groups of 1.5" or better at 100-yds. with both 180 & 220's.
Been accurate, reliable and fun - even with a short bbl.

The main advantage to the 700 bolt-action and a longer than 22" bbl. would be shooting the 'enhanced ammunition' available, giving you the .300 Win.Mag. like numbers.

MolonLabe416
November 24, 2003, 01:37 PM
A 20" bbl will shoot better than most people. Yes, you get more velocity from a 24", but can YOU (or me, not picking on you) use it? Most can't. A 20" or 22" bbl is much handier in the field. Of course, if you only shoot from a bench on a square range, than a longer bbl is moot. Depends on the application.

Brasso
November 24, 2003, 04:42 PM
The only advantage to a 24" barrel is a slight velocity gain, which is not needed unless you want to shoot past about 300yds and need a slightly flatter trajectory. If that's the case, just get a 7mm or .300.

Kestrel
November 24, 2003, 05:31 PM
What is the velocity difference between the 22" and 24" barrels?

Steve

Jaywalker
November 24, 2003, 05:34 PM
Remington calls it 20 feet per second per inch of barrel at that velocity level, maybe 25.

Jaywalker

CaesarI
November 25, 2003, 01:58 AM
With a .30-06 the difference between 22" and 24" isn't much. While a 24" is standard, a 22" won't cost you more in velocity than its worth in handiness. I might have some issues with an 18.5" .30-06, when it gets around 18.5-20" the ballistic difference between a .308 and a .30-06 approaches 0.

-Morgan

BusMaster007
November 25, 2003, 02:35 AM
That may be true except for the extra 40 or more grains of projectile going downrange...:D

My main thought with that 7400 was:
it wasn't a "Winchester Pre-64 Model 70 in .30-06". :neener:

When I chose the Autoloading Carbine by Remington, I knew exactly what I wanted in a .30-06...something short; powerful; quick-shooting; and able to 'get ammo anywhere, including neighbors when the SHTF'...
It was going to be my first and only rifle for a while.:rolleyes:

Of course, Remington became my preferred brand. And I got more rifles.

:evil:

Dr.Rob
November 25, 2003, 04:29 AM
Your deer/elk won't notice the difference.

I hunt with a 22inch compact fluted stainless barrel.. the last 2-3 inches is adjustable muzzle brake, not rifled. Actual barrel is 19-20 inches.

Dad uses a remington 760 Carbine, 18.5 inch barrel.

Past 400 yards you might notice a difference... up close, doesn't matter much.

Johnny Guest
November 25, 2003, 04:45 PM
The original question was, Shouldn't a .30-06 have a 24" barrel for optimum velocity? I believe only the rifled portion of the barrel, without regard to extensions, brakes, or comp chambers, has any effect on velocity.

Original barrel for the 1906 cartridge was just short of 24 inches, and this was the standard by which the '06 was measured for many decades, if not always. Ned Crosman, in his fine old work, Book of the Springield, rails against anyone who would tamper with this ordained-from-on-high standard. Claims it destroys the rifle's balance, ruins the ballistic integrity, and probably causes crop failures in Kansas. :D

Any time someone quotes the old, OLD, velocities, such as 2960 fps for somebody's 150 gr. load, the ammo company started out with a 24 inch, if not longer, barrel. As a matter of plain fact, though, if you go through all the arms company catalogs, you'll find that the majority of .30'06 rifles come in 22 inch trim. Some, indeed, are offered in 24 inch length. I believe friend and moderator Art Eatman has the only 26-inch '06 of which I am aware. He hunts in wide open spaces, mostly, and makes good use of all that barrel. He obtains actual velocities near equal to some of the old .300 H&H loads, when the latter are fired from the later model, truncated barrel rifles.

I've always been quite satisfied with the velocities from my Ruger 77 and Remington 742 rifles with 22 inch barrels. One should really test and sight-in and practice with each individual rifle anyhow, using the actual ammunition which will be used in the field. Printed ballistic tables are very interesting and useful for comparisons, but mostly for comparisons with other ballistic tables.

Only two comparisons are worthwhile, in my thinking - -
1. Two similar '06 rifles with different barrel lengths, OR
2. Two similar rifles, one in '06 and the other in another caliber, with both having the same barrel length.

You pays yer money and takes yer choice . . . . ;)

Best,
Johnny

Johnny Guest
November 25, 2003, 04:51 PM
- - - IF one stipulates use of two rifles, one a .308 and the other a .30'06, each with a 22-inch barrel, and using identical 150 gr. ammo, there is almost no practical difference in the velocities. (Again, working from published tables. :) ) When you leave this general area of barrel length, or go to heavier bullets, the .30'06 tends to pull ahead in performance.

Best,
Johnny

ken B
November 25, 2003, 10:44 PM
Now don't quote me, because i don't have the text near me right now, but the latest newstand issue of GUNS has one of Clint Smith's people at Thunder Ranch doing work with a 300 win mag that they cut 2" at a time off a Lilja barrel...here it is!

cut down to 16", nice big chart for data..

16"
2667 velocity
lost 350 fps from 24"
.5" group at 100
2 1/8" at 200
2.25 @ 300 yds

just an FYI...really good article and sharp looking rifle..
not trying to misquote Mr. Smith, but great article..

Ken B
North Texas

Art Eatman
November 26, 2003, 12:25 PM
For many years all factory data on velocity was based on 26" barrels. The trend toward lighter, handier rifles changed a lot of testing/reporting methods.

For much of my hunting, anything that would kill a deer within 200 yards is "plenty enough gun". At this sort of distance, barrel length isn't much of a factor. However, I've spent a lot of time in country where one's only shot of an entire season might be at 400 or more yards. That's why I went to a 26" .30-'06. That allows me the maximum velocity and thus the flattest possible trajectory for that cartridge.

In the FWIW department, the length has never been a problem in climbing to a tree stand or hunting in fairly thick cover. I've never had a problem in throwing it to my shoulder for a quick snap shot, either. :)

I guess it could vary with some of today's powders, but all the tests I've seen in such as the American Rifleman for the '06 or for conventional magnum cartridges indicate a velocity loss of around 70 ft/sec/inch as the barrel is shortened. It's less for such cartridges as the .308; the '06 is a bit overbore. (The .270 and .25-06 would also fall into this "overbore" category...)

:), Art

Jaywalker
November 29, 2003, 09:45 AM
Art,

Typo check? "70ft/sec/in?"

Jaywalker

Art Eatman
November 29, 2003, 10:10 AM
Jaywalker, about every ten years somebody at the American Rifleman gets curious about the effect on muzzle velocity of shortening barrels. ("Brush-busting" bullets, too, for that matter.)

In general, overbore cartridges lose some 70 ft/sec per inch of "chop". If you get around 3,000 from a 26" barrel, you can expect around 2,700 or so from a 22" barrel. This loss isn't uniform nor is it exact, from rifle to rifle or cartridge to cartridge.

Another generalization is that cartridges with a case design like the .308 are not affected as much, with a loss of roughly 40 to 50 ft/sec per inch. I guess this has to do with the comparative efficiency of the length/diameter relationships.

To me, this sorta explains why the .308 and the '06 behave pretty much the same in rifles with barrels of 19" or 20"...

Another factor in all this is that commercial ammo is loaded to a bit higher pressure for the .308 than for the '06. Ergo, in a long barrel with handloads, the '06 can provide 200 to 300 ft/sec more muzzle velocity for a given bullet weight than can a .308 with its typically shorter barrel.

(Dang, that's a lotta verbiage!)

:), Art

Jaywalker
November 29, 2003, 10:54 AM
Art,

I haven't read any of those "American Rifleman" articles, and I guess the issue is "overbore." Does it discuss discrepancy betweeen its findings and those of the published tables in Remington catalogs, or Lyman's 47th, for instance? They all show some version of the following table:


Bbl ch in Vel Range
2000 2500 3000
1 15 20 25
2 30 40 50
3 45 60 75
4 60 80 100
and so forth


Jaywalker

Delmar
November 29, 2003, 12:29 PM
Probably just me, but I look at the longer barrel lengths as "free" velocity boosters, and wish more companies made their rifles with longer barrels, or at least give us shooters the option.
Most of the longer barreled rifles tie you to a heavyweight barrel, which takes away a lot of the "handiness" of the firearm in the field.
The shift to the shorter barrels really doesn't impress me very much, even if it only costs 20 fps per inch.

Kestrel
November 29, 2003, 01:18 PM
Art,

What does "overbore" mean?

Thanks,
Steve

Publicola
November 29, 2003, 10:59 PM
for what it's worth the reason most people assume a longer barrel is more accurate has nothing to do with velocity. It's all about sight radius. A 26" barrel has a longer sight radius than a 22" barrel therefore a small discrepency in sight picture will affect the 22" barreled gun more than the 26" barreled gun. So over the years people assumed it was because of velocity rather than sight radius. No one really brought that up here but thought I'd throw it our there just for the hell of it. & hardly anyone uses iron sights anymore so barrel length doesn't matter as much as it used to as far as accuracy goes.

So even though a 22" barrel has slightly less velocity than a 26" barrel, it will be just as accurate (all things being equal). As far as practical accuracy goes if you can accurately judge the change in drop at 300 yards in the field then you're a much better shooter/hunter than I'll ever be.

I wouldn't worry about the slight loss in velocity. If I was using iron sights I'd worry about barrel length.

But practically speaking, if you know your trajectory then 100 fps or even 200 fps won't matter much in an '06. 2700fps with a 150 grain will do the same job 2900 fps with a 150 will do; you'll just have to adjust your aim a little (an inch or two) to hit your target.

But to directly answer your question you'll get optimum velocity with the longest barrel suitable. After a certain point the length of the barrel will start slowing down the bullet(dependent upon the burning rate & charge of the powder), but in an '06 I'd imagine this wouldn't happen till you're over 30 inches. (though I could be wrong).

& overbore (IIRC) means that the bore is small in relation to the case volume. In other words the case can hold more powder than the bore diameter can effeciently burn. Underbore would be the opposite - the case capacity not being able to surpass the burn capacity of the bore diameter.

buttrap
November 30, 2003, 06:20 AM
you can always make up a load using a faster powder to get the short tubes up the the factory speed to. The down is the shorter the barrel is the more the blast. I have a 18 inch 30-06 auto loader and that thing is the most nasty thing to shoot short of a 5 1/2 pound 50-70.

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