You are just being your usually self: a provocateur. No one can be that ignorant.
The 30-06 was used World Wide and powder improvements allowed the cartridge to operate around 42-44,000 psia. The 7.62 also had a 50,000 cup pressure limit. Getting into the argument about psia and cup is fruitless, but the 7.62 usually ran well under 50,000 cup.
The 223 round was not so much “designed” as it was a wildcat. The guys who came up with the round wanted a certain velocity at a certain range. I read the 1971 Guns & Ammo article
“The 223 is here to stay” by Robert Hutton. Robert Hutton was technical editor of Guns and Ammo magazine and must have been very wealthy as he owned a big piece of real estate in Topanga Canyon California called Hutton’s Shooting Ranch. The property is probably worth billion's now. Hutton’s article documents how he developed the 223 round. It was a vanity project by a rich elite who probably meant well. If you have any sort of technical background, it is apparent he is an amateur and his cartridge represents what an amateur would do. He took an existing cartridge, necked it up and down, blew the shoulder out, changed shoulder angles, he had a chronograph, got the velocity he wanted at distance. The crowning achievement in the article was punching holes in the wobble pot at 500 yards. That is about all the lethality testing Hutton did, punching holes in a helmet. He used the Powell Computer, a paper slide rule, to estimate pressures. He did not pressure test his cartridge he did not have a pressure curve. This cartridge was then adopted as the US service round. William Davis, the Government Technical Expert at the Icord hearings, said on the History Channel that the technical data provided the Government on the 223 round did come with a pressure curve. These guys developed a cartridge and never thought of documenting what the pressure curve looked like. Pressure curve is absolutely critical to the timing of an automatic weapon. How long energy is available, the maximum pressure and how fast it drops off is fundamental to the design of a automatic gas mechanism.
Hutton did not look at case hardness, taper, expansion or contraction. A professional would have looked at the expansion and contraction of the case in the chamber and adjusted case taper, thickness, and established case hardness in the sidewalls and case head. You would have to work with manufacturing to determine realistic hardness parameters throughout the case, but this is important as it affects the Young’s Modulus. As it turns out, the brass case 223 drags on extraction, there is not enough clearance between the case and chamber. Steel case is even worse. I have seen many failures to extract steel case ammunition on the firing line with AR15’s.
It turns out the 223 is fairly straight tapered. This was a fad, highly promoted by P.O Ackley, and widely copied. I am not a fan of very straight tapered cartridges. The one and only advantage of a very straight taper is maximizing the amount of powder you can get in the case. The wildcat era of the late 1940’s through the 1960’s was all about high velocity, and only high velocity. It was very one dimensional thinking, ignoring other aspects of cartridge design that are very important. One of the things you trade off for a straight case is that the cartridge does not “steer” well during feeding. Anyone can test this, which shape feeds better into the end of the tube, a taper, or a straight cylinder? Alignment to bore is important for feeding with all cartridges, but the really straight ones are going to jam up more often when alignment gets slightly out of whack. Straight cartridges will drag on extraction because the case walls are relaxing off the chamber walls in a straight line, not a diagonal. It turns out portions of the 223 case are still sticking to the chamber walls during extraction and a major reason for extractor lift.
Understanding Extractor Lift in the M16 Family of Weapons www.dtic.mil/ndia/2003/smallarms/din.ppt This is very undesirable as jams will get you killed in combat. Lots of good American Boys died in Vietnam with jammed M16’s in their hands. Ideally, the case will be fully relaxed off the chamber walls during unlock and there will not be any resistance between case and chamber during the residual blowback period. If you look at good case design, the Russian 7.62 X 39 and the recent Chinese service cartridge, both have more case taper than the 5.56 Nato and both were designed with steel as a case material. Both have nice thick rims, which is also important for machine gun rounds.
View attachment 860142
As an example of the well thought out nature of these Chinese rounds, the 5.8mm operates at a much lower pressure than the US service round. It only generates a 41,500 psi (284 MPa) chamber pressure which is marginally higher than that of the old single-base propellant used by the vintage 7.62x39mm and much lower than the 5.56mm M855/SS109’s 55,000 psi (380 MPa). The current pressures of the latest 5.56 rounds have been kept out of public view, but it seems to be in the range of 62,000 to 65,000 psia. Considering the proof round is 70 kpsia, the Army is operating its cartridges at pressures that are guaranteed to crack bolt lugs very quickly. You see, the AR15 was designed for a 50 cup round, not a 65 kpsia round. Lower pressures means fewer failures to extract when the weapon gets hot, or the Trooper is in a hot environment. It is always true that doing the job at lower pressures is better than doing the job at higher pressures.
I have shot next to the service rifle teams. I saw them using Federal Gold medal match out to three hundred yards, and depending on the year, and service, they were either rolling their own, or using Federal and I saw the Marines using Black Hills match at 600 yards.
And, these guys were blowing primers. I don't have the Marine Black Hill ammunition picture, but the same day, same relay I picked these AMU cases, I have a hand full of Marine Black hill with blown primers.
View attachment 860143
The 223 is operating at such high pressures that it takes virtually nothing to create a blown primer. And that is a direct consequence of high operating pressures.
Implicit in your comment is the assumption that US arms and ammunition are picked for their technical merit. That is not true. The procurement process is highly political with groups inside and outside the Ordnance Bureau's fighting over doctrine, but mostly, over budget. The Military exists to serve the industrial sector, National Defense is way down on the list of actual priorities. This is the primary reason weapon systems are so expensive, but salaries are low and facilities are always falling apart.
Given the United States pre eminence post WW2 it makes sense, given massive foreign aid, the free weapons and munitions, we gave to "Allies" that they would adopt our cartridge. We bullied the British from adopting an excellent mid range round. If however, you notice, our European allies have created superior side arms to shoot the 5.56, and when NATO finally breaks up, they will probably adopt a better round.
The US never developed this round.
View attachment 860144
The Communist block did better in their selection of post WW2 service rounds, and I would say, based on distribution, the 7.62 X 39 is probably the number one service round in the world. Considering it is a 1940's design, it is still an outstanding intermediate round. That round was obviously selected because of its technical merit.
And geezers, China is not the Nation that you remember during the Kennedy era. China is now the lead in artificial intelligence. You probably don't understand what that means, but it is big, big, big. And you are looking at my post through a Chinese made electronic device. And, the chips were probably designed in China, or at least, they all will be in less than a decade. American Universities graduate more Chinese National PhD's than they do native Americans, and have been doing so for decades now. Someone can research the exact start date, but it has been awhile. It won't be long till the Chinese GDP passes the US GDP. We ought to take China for serious and it is only our ignorance, racism and hubris that prevents us from recognizing the professionalism that China exhibits in all areas of industry. The US ought to be buying modern Chinese small arms and issuing them to our troops instead of using the 1950's Stoner rifle and the Hutton wildcat round.