Re: revolutions per minute debate
I'm not going to disagree with you. I was trying to illustrate that the rifling twist ratio is only part of the picture regarding the stability of a bullets rotation. This ratio must be coupled with MV to equal some RPM. We get used to saying that this or that bullet fired from this or that cartridge will either stabilize or not. What we really mean is that X length bullet of Y weight and Z caliber needs to spin at some approximate RPM. I wrote my illustration with no regard to an actual example and used numbers that had been used before in the discussion.
I also used "somewhat" and "almost" in paretheses for exactly the reason you mentioned. There is the transsonic issue but a bullets stability in crossing it (I believe and I may be wrong)is more a function of RPM because the speed of the bullets crossing it is always about the same. Some remain stable and some not as much. Yes there are other factors that contribute to this transition as well.
Yes, a bullet spinning like a top on a table must spin faster than a bullet in supersonic flight to stay stable. That spin rate is measured in RPM for both bullets. It is not correctly measured as a twist ratio. That's all I meant.
GRAVITY. It's not just a good idea. It's the LAW!