30-06 vs 338-06

[ArchAngelCD]

I'm confused here but that's not rare.

Using Hodgdon data.
The 30-06 shooting a 200gr jacketed bullet over 53.7gr H4350 will achieve 2580 fps @48,400 CUP.
They only supply data for up to 220gr bullets.

The 338-06 shooting a 200gr jacketed bullet over 62.0gr H4350 will achieve 2729 fps @54,300 PSI.
They supply data for up to 250gr bullets.

They use the same case for goodness sake so why can we push the 338" bullet so much faster? Why can't we use the same charge in the 30-06? I'm sure it has something to do with the wider bullet but I know very little about why. I'm also at a loss as to why they supply data for bullets 30gr heavier than those in the 30-06. The 338-06 will push a 250gr bullet as fast as a 30-06 will push a 200gr bullet with the same powder. Again, it's the same darn case!!!

Can anyone clear this up for me?

 

[adcoch1]

I probably can't completely clear it up but here goes: the normal 338 bullets available come in those heavier weights, and be bigger around, achieve that weight while not filling so much of the case's volume with bullet. Thereby leaving more room for powder. Also, there arent a lot of 30 cal bullets over 220 grain. Another point is the six thousand pound pressure difference. The 338 has a bigger case mouth to let that pressure pass and keeps the charge from spiking as bad as the 30 cal neck would.
Can you load a 30-06 that hot? Sure, but you may run into some issues with pressure spikes... I could be wrong, but this is how I understand it.

 

[LoonWulf]

Playing with QL similar pressure loaded to the same coal give me 2730 and 2589 respectively, at the same 56k projected.

Go to a slower powder like imr7828ssc and 56k will give you 2690 with a 200grn bullet.

Now this is just playing on qls, but it does illustrate the need to chose the correct powder/burn rate to match case capacity vs bullet weight/caliber.

Ive also done some heavy loads with 7828 (compression became an issue) and the 208 amax, ive got my load set but have not chrono'd it yet. I might get a chance this week.

 

[Berger.Fan222]

A larger caliber bullet has more base area to push on, so the same pressure curve produces a larger force.

The base area of a .338" bullet is 20% larger than the base area of a .308" bullet. All other factors being equal (bullet mass, etc.) the applied force will be 20% larger, thus a larger acceleration and a larger muzzle velocity.

But the advantage you gain by cross sectional base area in the barrel are lost in flight with lower BCs for bullets of the same mass and shape. For retaining energy downrange, a 200 grain .308 bullet has the advantage.

So for shorter range, bigger game, I like the .338-06. But for long range, I'd prefer the 30-06. In practice, you can use a 30-32" barrel for the long range 30-06 and launch high BC 200 grain bullets near 2800 fps by optimizing powder choice and seating depth.

 

[jmr40]

The 338 bullet is shorter and has less surface area in contact with the barrel. Anytime you increase bullet diameter you can get more speed with equal amounts of powder. At 1st glance it appears the 338-06 has the edge, but it has 2 things against it.

Below is a representative photo showing a high BC,SD bullet compared to a low BC,SD bullet.



The short stubby 200 gr 338 with poor BC's bullet may start out faster, but within 100 yards the 30-06 shooting the same bullet weight with very good BC's is faster and will have more energy. Also it is a bullets length in relation to weight that determines how well it penetrates on large game, not just weight. This is known as Sectional Density, (SD). Within the same caliber longer and heavier go hand in hand. But when you compare different calibers it is harder to determine. You have to go up to 250 gr in 33 caliber you get the same penetration that you'd get with a 200 gr 30-06 load.

On paper 338-06 looks better at close ranges with 200-225 gr bullets, but in practice 30-06 out performs it at all ranges with 180-200 gr bullets. If you step up to 250 gr in 338-06 you start seeing some real advantage for 338-06. Once you get to 250 gr the BC's and and SD's are similar. But shooting 250 gr bullets from a 338-06 compared to 200 gr 30-06 starts to get into serious recoil exceeding 300 WM. If you're going to get that much recoil anyway then it makes more sense to step up to 300 mag and shoot 200-230 gr bullets.

 

[ArchAngelCD]

Thanks for all the comments so far. The information provided is appreciated. I'm not turning in my 30-06 any time soon. This question has intrigued me for a long time and I finally asked.

A larger caliber bullet has more base area to push on, so the same pressure curve produces a larger force.

The base area of a .338" bullet is 20% larger than the base area of a .308" bullet. All other factors being equal (bullet mass, etc.) the applied force will be 20% larger, thus a larger acceleration and a larger muzzle velocity.

That is very helpful as is jmr40's post below it. That is so simple I'm a little embarrassed I didn't realize it. Thank you.

 

[Nature Boy]

That helped me too. Thanks for asking AA

As I was reading you post I was thinking the same thing. "why wouldn't everyone rechamber their .30-06 to .338-06?"

 

[Wreck-n-Crew]

Another point is the six thousand pound pressure difference.

One's Cup and Ones PSI. I don't know the conversion. V V V V

The 30-06 shooting a 200gr jacketed bullet over 53.7gr H4350 will achieve 2580 fps @48,400 CUP.
They only supply data for up to 220gr bullets.

The 338-06 shooting a 200gr jacketed bullet over 62.0gr H4350 will achieve 2729 fps @54,300 PSI.
They supply data for up to 250gr bullets.

 

[adcoch1]

Dang! I missed that! Thanks wreck-n-crew.

 

[Wreck-n-Crew]

I miss stuff too, more often than id' like!

 

[Varminterror]

Here's a reality - they're the same case, chambered in the same rifles, so both can be loaded, regardless of what SAAMI might say, to the same pressure. SAAMI claims the 338-06 can be loaded to 63kpsi, while the 30-06 only to 60kpsi. The Whelen they list to 62kpsi, and 270win to 65kpsi... There really shouldn't be any reason to have any difference among these cartridges in the real world. If the action will sustain 65kpsi with a smaller bullet and 63kpsi with a larger bullet, why stick the Grandpa 30-06 with such a low number?

BUT.... Even if they were loaded to the same exact pressure, either uploading the 30-06 over max, or under-loading the .338-06... Pressure = force applied over an area. So if the pressure is the same in both, the 338-06 has a larger bore area, so there's more force applied to the bullet, and you'll get more power out of the business end.

The shortened bearing surface is another contributing advantage to reduced pressure for the same powder charge OR a greater charge (relatively) to hit the same pressure level. More velocity for the larger diameter with the same pressure and same bullet weight.

As others have mentioned, there ARE disadvantages for the 338-06 when you talk about heavy for caliber bullets in 30-06 and light for caliber bullets in 338 A-square. You lose aerodynamics, of course, since the equal weight bullet is a lot shorter and more blunt, but you also lose penetration and killing performance, because your SD drops too. Despite how slow they are, I prefer 225's and 250's in the 338-06 to give me back some of that penetration. I can deal with the trajectory consequences of shooting a slower bullet, but there's no way to make up for lost killing performance at the impact point, so I don't play with the 200grn bullets in the 338 A-Square.

I LOVE my .338-06, if it were a stainless rifle instead of blued, it would probably be my favorite deer hunting rifle. But there are specific realities to deal with when you hook a big trailer to the bumper of a truck with a relatively small motor. For anchoring medium game and big game at short to moderate distances, the 338 A-square is hard to beat.

 

[Wreck-n-Crew]

Interestingly enough the 270 Win was not given the 65,000 PSI max until the 60's. It was once listed as 52,000 PSI. Of course that was before more modern measuring devices came into play and rewrote what once was thought to be the same PSI and CUP (or the copper crusher method as it was known).


History


The Lyman reloading manual is one of my favorites. It’s clearly written, a pleasure to


read, and it sheds some interesting light on the history of terminology in the measurement


of chamber pressure. Before about the 1960's the only measurement system we had for


chamber pressure was the copper crusher method. Up until that time, what we now call


CUP was commonly known by two different names: CUP and PSI. The two were used


practically interchangeably. Of course, this use of PSI was incorrect. It wasn't much of a


problem until piezoelectric and strain gauge systems became commonly available. These


systems, of course really do measure in PSI. When they arrived on the scene, it caused a


lot of concern and confusion. “For years, 52,000 PSI (crusher method with erroneous


designation) had been pub lished as maximum for the 270 Win. Suddenly, there were new


publications showing 65,000 PSI …as maximum.”1

From: https://www.shootingsoftware.com/ftp/psicuparticle2.pdf

 

[DM~]

I'm going to skip all the paper ballistics and hype surrounding these two cartridges and go directly with MY experience with both cartridges.

I fired my first 30-06 in the 60's and by the time the 70's rolled around, I had my first .338-06 in my hands. I already knew how the 30-06 performed on big and "bigger" big game and started trying many different bullet and bullet weights in the .338-06...

Personally, I don't need even a 30-06 to kill a deer or blk. bear, so I don't need .338 bullets to kill them either, BUT I was focusing more and more on moose and brown bear, so I was trying bigger more powerful cartridges.

I knew the 200 NP was very hard to beat out of a 30-06, so it was going to take something pretty good to beat that on bigger big game and I got started with 210NP's... Soon I moved up the ladder to 250NP's and 275 Speers and settled on those two as what "I" needed to get more horse power than a 200NP out of a 30-06.

I already had been through the 300 mag., 375 H&H, .338 Mag., and even the 340 WBY... I don't want to have to loose an extra round in the magazine, nor did I want to have to have the longer bbl. you need to get the extra power and muzzle blast muzzle blast they give, plus in some cases, extra recoil.

I shot several moose, deer, caribou and brown bears with my .338-06 and love the way it performs on the bigger big game! An example of how it works is, I jumped a wounded brown bear and hit it in the left front shoulder as it turned (about 50 yards away) that bullet (275 Speer) broke that shoulder and penetrated completely all the way through the bear exiting out the right rear hind quarter... The bear dropped, got up and I hit it again right in the butt hole where the bullet traveled on a slight up angle and demolished 12" of back bone before exiting up through the hide. The bear was dead before I got to him...

Both bullets expanded well and did a lot of damage... And THAT's what the .338-06 is good for, and shines over the 30-06.

I still have that rifle but I no longer hunt brown bear or even moose, so it's become a safe queen... Here it is with just a small portion of meat it has put in my freezer!



DM

 

[Captcurt]

I have wanted a 338-06 for 30 years but have no use for it now. I will never hunt anything larger than a whitetail now that I am over the hill. Never could fathom why the 35 Whelen was more popular when you had a better BC with the 338 cal bullets. A 225 gr should be the best of the lot, but this is just speculation.

 

[GooseGestapo]

Likewise.
I built mine in '03 for elk and moose. Hunted and shot an elk and several deer with it. I too wanted (but didn't NEED) more power than a '06 without giving up extra magazine capacity.
I have several other equally capable guns, and too, won't likely ever get to hunt elk, moose or bear again. Getting too old and feeble.

 

[Bart B.]

SAAMI claims the 338-06 can be loaded to 63kpsi, while the 30-06 only to 60kpsi.

Where? SAAMI's latest specs don't list that cartridge.

Is the 338-06 A Square the exact same round but a different name?

 

[stringnut]

Where? SAAMI's latest specs don't list that cartridge.

Is the 338-06 A Square the exact same round but a different name?

338_06 a square is the round A Square had SAAMI standardized. Before that all were wildcats. Weatherby chambered them for a while. I don't know if anyone else chambered a rifle for it.

 

[Bart B.]

Are case and chamber specs for the original and A Square version the same?

 

[readyeddy]

I once asked the same question comparing the 30 06 with the 35 Whelen. The Whelen will achieve significantly higher velocities with heavier bullets when compared to 30 06 loads. I was baffled.

What I was told, on THR, is that the larger bore creates a larger area or volume in which the powder is burned, so you can burn more powder and achieve higher velocities with the larger bore.

 

[ArchAngelCD]

I was not confused about CUP and PSI and I did realize the data I posted was not the same unit measure. I also realized there was not a difference of 6,000 psi. It's almost impossible to know the difference between those two numbers since there us no real conversion.

Like I said above, I completely forgot about the pressure action on a larger surface providing more push in the .33 cal. over the .30 cal. That fact alone,puts the numbers in perspective.

 

[zb338]

Why use the .338/06 when you can just re-barrel the good old .338 Win. Mag.
in the same rifle. It works in a standard length action and isn't really much
of an over bore cartridge. It has an excellent reputation as a big game caliber.

Zeke

 

[DM~]

338 mag needs a magnum bolt too...

DM

 

[Varminterror]

Where? SAAMI's latest specs don't list that cartridge.

Not sure why it's not in the 2015 revision, I assume it's simply because A-Square went out of business in 2012, and nobody else was making rifles for it and only Nosler is loading for it.

If you pull out your 2013 revision, the 338-06 is included. Page 10, directly following 338 Winchester Magnum.

SAAMI Velocity & Pressure Data PDF of 2013 Revision

Is the 338-06 A Square the exact same round but a different name?

.338-06 A-Square is the same as the original, if you could ever say any wildcat which is standardized is the same as "all of the originals" which went before. A-Square took on the chambering, did sufficient development, and they then were the original submittors to SAAMI for standardization.

There IS also, or WAS also, a ".338 A-square," I forget exactly the parent case, but it's a different round than the 338-06 A-Square. I ordered my dies custom, they just say .338-06, but my brass, when I don't use .30-06 brass, is all nosler .338-06 A-Square.

 

[ArchAngelCD]

Why use the .338/06 when you can just re-barrel the good old .338 Win. Mag.
in the same rifle. It works in a standard length action and isn't really much
of an over bore cartridge. It has an excellent reputation as a big game caliber.

Zeke

Several reasons and one being I'm not asking about the .338 Win Mag. I'm asking about the 338-06, a cartridge that shares a case with the 30-06.

 

[GooseGestapo]

.338-06 A-Square is same as .338-06. Art Alpin just added his trade mark. My Lee .338-06 dies are marked Ackley so as to avoid the "trade mark" issue. NOT ACKLEY IMPROVED!

The advantage of the .338-06 is ready availability of '06 brass, extra 2 rounds capacity over magnum. Almost same ballistics with 10-15% less powder, less recoil.
I've seen 3,100fps from 180gr; 2,900 200gr, 2,800 210gr-215gr; 2,700 225gr; 2,600 250gr.
Most accurate loads run ~70-100fps slower.
Most accurate load from my rifle is 250gr Hornady Interlok at 2,550 over 58.5gr of IMR4350. An acquaintance had a .338winmag A-Bolt w/26"bbl that got 2,650fps with max published load. My bbl is 24".
Enough said!