As to not highjack someone else’s thread, I thought I’d start another.
I have done a lot of bullet testing over the years using the Bullet Test Tube. In that testing, learned several things. First, there aint no such thing as an ‘efficient “ cartridge. They all will blow unburnt powder into the media. But over the years I have observed that when using a magnum primer or a standard, the magnum always sends less unburnt powder into the media. What does that mean ? The only thing it means for sure is that less powder gets blown into the media.
Seems in the gun industry, a piece of info like that gets twisted into several other things. But in my mind, it only means exactly what “that” test proved.
Charlie