Home Forums Hunting & Shooting Ask The Gunwriters 338-06 standard or 338 A square

Ok fellas, I am building a 338-06 but recently its been brought
to my attention that the 338-06 A Square is not the same as
a standard 30-06 necked up to 338. I have looked in several
reloading manuals and the dimensions differ in reguards to
shoulder angle. Can some one clear this up for me. <img src="/ubbthreads/images/graemlins/frown.gif" alt="" />

They are one and the same. A-Square just worked the SAAMI effort for the standard 338-06 to "legitimize" the round. The drawings in the Speer #12 and A-Square manuals shows all to be the same save for a 30 minute difference in shoulder angle which is meaningless with proper headspace. I have been shooting one for years and use Winchester 30-06 brass and a 338 expander plug and do not bump the shoulder. I have also fired the factory Weatherby 338-06 A-Square load with no issue. Cliff LaBounty did the rebore/chamber on mine long ago. Used it just a week ago to take a nice bull elk.

Thanks for the info, I want to get the right dies for what I am
building.

How can they be the same if one has a 17 degree shoulder and the other has a 34 degree shoulder?

I admit that the a-square cartridge will chamber in a 338-06, but even with proper headspace it is headspacing on the point of the shoulder, not the shoulder itself.

Loads that are sized with the 17 degree shoulder dies will not chamber in a rifle cut for the a-square cartridge.

Better make sure to get the right dies, or it will be harder on your brass.

I guess I will be putting a call into Redding tomorrow. There are to many conflicting drawings out there. I am about to
change my mind and go with 338 win mag.

just get the standard 338-06 thats what i did. i can tell you 338-06 A-Square feed, chamber and fire just fine in mine. course you cant go wrong with its big brother but i didnt need the extra velocity of a magnum.

Rattler

My Nosler 4th and 5th edition manuals give identical measurements
for the .338-06 and and the .338-06 A Square.

Am I the one that is confused?

1B

1B

No! You are not the only one who is confused. In different manuals, I can find about 5 or 6 different versions of same. The version is the Nosler is what I consider "Standard". However, even the drawing in the A-Square manual is different. <img src="/ubbthreads/images/graemlins/frown.gif" alt="" />

But I also believe the differences are negligible. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />

the9.3guy

There is a fair amount of difference in these two calibers. I was nearly certain, but before I made a post I called Dave Kiff at Pacific Tool. Dave is coming here in a day or so and will post what the differences are.
Charlie

Charlie,

Thanks for letting us know... I'll be looking forward to your post. <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />

the9.3guy

Ditto, I was hoping Charlie could shed some light on this.

FWIW.

This discussion is complicated enough to keep our terminology
as clear as possible. Cartridges of the World mentions a 338
A Square that is a muxch hotter belted round! Obviously it
sleeps with the fishes in terms of frequency of use these
days. The .338-06 A Square is the critter in question here.

1B

Even though there have been attempts to make the .338-06 a factory round (as with A-Square) so far it has pretty much resisted any such effort. It will apparently always be primarily a wildcat, and the "standard" version will probably always be the .30-06 necked up, with no changes in the case except bore diameter.

The two .338-06's I've had featured this chamber--and while .338-06 A-Square ammo would fit OK, it did not always go bang. This was partially due to the fact that it was sent to me for "field-testing" during the last days of Art Alphin's total control of the company, and was some of the worst ammo I've ever seen. The bullets were seated visibly out of round, there were varying dimensions in brass, headstamps were half-off the cartridge head, etc. Today I probably wouldn't even fire the stuff, but I was more naive then.

How much you want to fool around when making wildcat cases depends on your temperament and enthusiasm for rifle-dinking. I have too many rifles to waste time on weird shoulder angles (even Ackley) which don't make any real difference in the field. If I ever do another .338-06 it will be the standard version, which simply requires running the neck of a boring old .30-06 case over an expander.

MD

Didn`t Weatherby give some life to the A-square round by chambering it at one time??

yes, then they screwed up the chamber and ammo dimensions. Ammo was just a 30-06 necked up to .338, chamber was cut to 338-06 A-Square dimensions. Gave the brass a .006 run at the chamber on the first firing and left a significant bulge just ahead of the case web.

Here's a twist. The factory Redding label on my dies reads "338-06". The label stuck on there by the retailer with the bar code reads "338-06 A Square". So which label is correct. Hrnhuntr, I wished you would have never opened this can of worms. The good news is, the rifle shoots like a dream. I guess I shouldnt worry to much about it.

Roads

Roads, I am doing the standard but the two variations that Redding lists are 338-06 A Square and 388-06 imp 40. Do
to the fact I won't be full length resizing anyway it isn't a
huge deal but I would like the dies to be a match to my
chamber.

Not sure where the 17 degree vs. 34 degree came from? Last I recall 30 minutes is 1/2 a degree so that is the shoulder angle difference between the Speer and A-Square manuals. I have both RCBS and Redding dies, both say 338-06. I have used Weatherby 338-06 A-Square (Norma brass) ammo and brass as well. All works fine.

I talked with Redding's technical services today.

At first the guy said only two .338-06 sets are
made a standard .338-06 and an AI. Then he checked
and said a .338-06 A Square is also made but they are
indentical to the .338-06. Why then mark them differently
says I? The A-Square was proprietary says he. Hugh?

The beat goes on...
Why in the hell would WBY withdraw rifles b3ecause of case problems,
if the two cases are indentical?

All this is by way of reminding ourselves that precision reloading
is a chimera.

1B

Because the chamber specs and the cartridge specs don't match. If their ammo was the correct size, or their chambers weren't so large they wouldn't have had a problem. .006" is a lot of slop between the cartridge and the chamber. What good does it do to prepare concentric ammo with minimal runout only to throw it in a chamber that starts it into the barrel at an angle?

Had they just necked up a 30-06 to .338 they would have been fine.