I started into the thread above & about 1/2 way down the first page gave up. It's the usual one or two dick-waving campfire experts that have only read about something, repeating it over & over 'til it becomes fact against other people with some actual knowledge of the subject.
Nosler #8 says the 338-06 A-Square has 17*30' shoulder & that standard 30-06 brass & a tapered expander is all that's needed. Sierra VI says the shoulder is 17*16'. Damned little difference. Not sure where the 34* thing came from. If there's concern go with a plain old 338-06 with the 06 shoulder. I dont own an A-Square & have never seen one in person, but I do own & shoot a 338-06 Ackley. The rifle was built about 30 years ago to get the 210 Partition to lower end 338 WinMag speeds. It was successful. The barrel is 25". We were going to test fire at full barrel length & then shorten as needed, but balance is perfect & it shoots pretty good so it stayed full length. It might have been enlightening to see how much velocity loss per inch there was. It's just fine the way it is. Using about 10 gr. less powder than 338WinMag, a case full of H4350 or RL17 in WW brass just squeaks past 3000fps.
The reason I went with the Ackley is that I was buying 1/2 the reamer anyway so might as well get something different. Both the Ackley & standard 338-06 were wildcats back then so dies cost the same. Like the improved 35 Whelen there is not a whole lot of improvement capacity wise, but there is some. I doubt that anything shot would be able to tell the difference. Since it's not a Whelen or a standard 06 the low SAMMI pressure spec for those 2 means zip. I load mine warm but brass life is excellent, primer pockets remain tight, & with the 40* shoulder case trimming is less than rare. If using an 06 case it will fireform about .030-.040" short & takes about 8 or 10 firings, or more, to get to max case length. I've also used 280 Rem & 35 Whelen brass which may need trim after fireforming. The 280 will need trim before loading after expanding the neck & pushing the shoulder back.
Edit: Good luck finding 338-06 A-Square ammo. A-Square is gone & Weatherby stopped loading ammunition. If you buy an Ackley you *should* be able to shoot factory 06 necked up with no trouble. It depends on who does the work. Minimum spec brass or a sloppy chamber (length=headspace) may give you incipient case separations maybe on the 1st firing. Since it's a handloading proposition, you can control the headspace. My sizing die is set with no reason to move it... ever. This took some fiddling & lost a few pieces of brass before all these nifty measuring tools were available & we did everything by feel. At the same setting I can resize fired brass or make new without headspace problems. I'm liking the idea of Whelen brass more & more due to the ever so slight 2ndary shoulder that gets formed with the initial sizing down, but 280 or plain old '06 works too.
Thanks!
Part of the 17 vs 34 degree shoulder angles is SAAMI vs. European standards (they use both sides of the case for the total angle vs. just the shoulder by itself).
Also, good tip on using 35 Whelan brass, though it sounds like regular ol' 30-06 might be a good way to go too!
