In the one case the full 45kpsi acts on the bolt. In the other 20kpsi is taken up by the brass and only 25kpsi acts on the bolt. Depending on the chamber pressure and brass annealed state.
Where did these numbers come from?
Greasing or oiling cartridges before firing is not a great idea as this increases bolt-thrust considerably.
This is an Army coverup over 100 years old. The Army was building M1903 in Arsenals with no temperature gauges, (except for sight springs!) and temperatures were judged by eye. Eyeballs, as Hatcher says, could not control temperature and lots of receivers and bolts were burnt. And then, there were perverse incentives in place. Forge shop workers were paid piece rate. Therefore, they had an economic incentive to heat billets as hot as they could, as that allowed them to stamp the parts out faster.
At the time, the cupronickel jackets on bullets fouled something awful. Shooters found dipping their bullets in grease absolutely prevented jacket fouling. They did not know, that the rifles they were shooting were structurally deficient. When "perfect" Army rifles blew up with "perfect" Army ammunition, the Army blamed the grease. "It increased bolt thrust". The Army claimed grease was in compressible, which it mostly is, (I don't have any bearings that work at 50K psia, so how knows at those pressures) but what they did not mention was, grease flows
30-06 before and after firing
Grease goes up the barrel, and out the chamber.
Sure oil and grease "increase" bolt thrust. So does polishing the chamber, and worst of all, adding powder to the case. This "increased bolt thrust" reminds me of the Movie Amadeus where the critics of Mozart claimed his music had too many notes. Well, what bolt thrust are weapons designed to take? And are weapons weakened assuming the cartridge reduces thrust? For the second, of course not. You don't get any meaningful reduction in bolt load unless you stretch cases to the point of case head separation. If the case does not stretch, it is not carrying load. Zero chamber clearance cases don't stretch, therefore neck sizing increases bolt thrust. Where are the warnings not to neck size?
The Army never admitted that they built bad rifles in underfunded factories, instead the Army lied about "increasing" bolt thrust and other nonsense. At the same time, the Army knew that the Swiss were using greased bullets, had to know the British were dipping their 303 Cartridges in oil, before shooting in Lee Enfields, had to know that greased bullets were used by the Austrians, the Russians, and the Italians. And, Hatcher knew of the oilers used in delayed blowback machine guns. By the time you get to WW2, the Oerlikon, the most popular 20 mm machine cannon, was using greased ammunition. I believe the Army alone purchased 200,000 Oerlkons. The Oerlikon and the Hispano machine cannon used greased ammunition and were used in planes, trains, armored vehicles, emplacments, etc, etc. The Japanese, Germans, and Italians used the things, or variations.
Why anyone should believe the Armed Forces about anything is beyond me. Marines and their families were drinking poisonous swill at Camp Lejune for decades. Many children came down with cancers and died. And it was all denied, covered up.
The Few, the Proud, the Forgotten. This just happens to be a one big lie, and I don't have the time to create a known list of DoD lies and coverups. Veterans know how their chain of command acts.
One hundred and twenty plus years after lying about the cause of low number M1903 blowups, the Army shamelessly continues to promote the coverup.
From a 2019 publication:
these guys are least are trying to dispel the misinformation:
So what do you believe, your eyes, or the Army?
