You completely missed the point of the test. The purpose of driving the bullet through manually was to determine whether or not barrel expansion could be induced SOLELY due to the passage of a hard bullet, thus eliminating the influence of chamber pressure. It was. This has long been known to be true and was confirmed by Woodleigh's tests.

What you are speaking of is no revelation. The point isn't if the barrel expands {of course it does}, but whether the barrel expands beyond the elastic limit. The barrel expansion might damage ribs, etc, even if the elastic limit is not exceeded, but that is not the same as saying OSR "spiraling" has occured.

One more time, no one has EVER demonstrated that chamber pressure has ANYTHING to do with this issue.

It is completely relevant to ask; "At what pressure does this occur?"

Remember, nobody is limiting their discussion of pressure to the chamber anyway or for that matter saying that excessive pressure has occured, tho it is admittedly hard to believe that such a circumstance would not occur.

Also remember, there must be sufficient energy imparted to the bullet to cause the displacement of rifling, regardless how hard the bullet is. In a gun, that energy is imparted by the expanding gases of the burning powder, and those expanding gases create pressure. To ignore pressure throughout the length of the barrel is to ignore the source of the energy necessary to alter the shape of the barrel {however small}. To ask "At what pressure does this event occur?" is completely logical. For the sake of argument, pretend that this event occurs at completely "normal" pressures. It is still relevant to investigate the pressures. I'm not sure why you have a problem with this.

Also remember, at this point on this Forum, nobody has, in fact, "demonstrated" the event. No pix, no docs. Just discussion. Agreement by some that it occurs, and something akin to disbelief by others.

Ah. Standard response for this string. Woodleigh lied. How impressively credible and constructive. Probably from a certain mono-maker that's done no testing at all.

Nobody said Woodleigh lied. Why did you ask that? In fact, if you are referring to the experiment with the hydraulic movement of the bullet thru the bore, it is accepted as fact. I've not heard any argument against it. I don't think the experiment conducted by Woodleigh is particularly earthshattering. The liquid is not compressible, so anyone familiar with hydraulics on a farm tractor knows extremely high forces can be applied using hydraulics. Again, I'm not sure why you brought up Woodleigh. The point isn't that Woodleigh lied. The point is twofold;

1} Was the elastic limit of the barrel material exceeded by the hydraulic test??

2} Does a hydraulic test replicate the forces of expanding powder in the barrel and the application of force against the rifling, i.e. is a steady application of force the same thing as a pressure curve as existing in a gun barrel??

I think you answered #1 and the answer was no, {correct? If not, maybe I misread that part}, and at least pointing to a possible answer of #2 is the fact that while it is to some degree informative and definitely interesting as an exercise, we don't normally squirt bullets out of gun barrels with hydraulic fluid.