Its been a long time since a 50kpsi 30-06 M2 round was fired by the U.S. Military.. Regarding your link, I would love to verify your statement about M80 pressures, but I'm not going to search through a 325 page pdf to find the relevant line.
Posters quoting SAAMI spec maximums for average pressures of issued military ammunition, don't know what was out in the field. The pressure limits for the 30-06 were set prior to WW1. Powder technology improved so much that if you look at the historical record, or put it this way, find an example of the 50,000 psia military 30-06 cartridge. One older shooter I met, he loaded ammunition at Badger Army Ammunition plant. He actually determined the amount of powder in the case, measured velocity, measured pressure. The WC852 he used, produced the desired velocity, and the pressures were so low, that as he said "
we loaded for velocity". He never ever had to worry about exceeding the cartridge pressure limits.
And that is all to the good. What is lacking from all the clever quotes of SAMMI maximum documents is an understanding that if you can do the same job at lower pressures, you are better off doing that job, at lower pressures. Some drivers never figure out why their engine smokes, and that it is somehow related to the burn outs they do between each and every traffic light. Military ammunition is not treated with kid gloves, it gets bounced around, cooked in containers, cooked in the sun, sometimes the troops have to use the stuff in very hot, nasty places. And, they have to shoot until the enemy goes away, and that might mean some hot weapons. High initial pressures only create real problems for the troops. Lots of good American boys died in Vietnam due to the Army Ordnance Bureau bumping up the pressures in the cartridges of the era. Their M16's jammed. Dead Troopers and cash awards for the Army Ordnance Civilians back home, that's what you call American Justice. Jams are not an academic issue when you have a AK bayonet in your chest.
The Chinese 5.8 X 42 mm is operating 36,980 to 41,970 psi per Wiki. I think the Chinese had some real professionals determine their cartridge requirements. You know, American Universities graduate more Chinese PhD candidates, in Science and Engineering, than CONUS born Americans. Maybe the US Army Ordnance Bureau needs to hire some smart Chinese Engineers! You know, guys who can not only add and subtract, but won't drool or fall asleep in meetings.
I got to talk to Korean War veterans, and a few WW2 veterans, they never ever had the sort of jams, mis feeds, malfunctions that become common once the M16 was adopted. The Garand was extremely reliable, every where. The thing was used in the Aleutians, the Middle East, and in the jungles.
As for the M14, I found even fewer Vietnam veterans who used the thing, but it was extremely reliable, and guys who had it, tried to keep them, because the first M16's were POS. I found some early M118 data, the stuff was running lower 40 kpsia with ball powder.
The 303 Brit MKVII round was 39,000 psia max, machine gun cartridges were bumped up, but the rifle ammunition was nice and sensibly low pressure.
I too have reloaded thousands of LC 5.56 and by gum every single one of them was WAY long...like .025+ and I don't think it's coincidental that cutting them back to the normal .223 length removed pretty much all of what had been crimped. If you get ammo like this with the long neck crimped tightly into the cannelure, it must have somewhere to go to release the bullet or the pressures will naturally go skyward. Unless you have a rifle with 'Match' chambering I think most manufacturers will err on the side of caution and leave the throat a bit on the long side even in .223...just in case. But never say never so if you're not sure about the chamber or ammo match...check.
