They don't. But, they use some kind of closed-breech test barrel of some length (usually very much impractical lengths outside what is considered normal for the cartridges). In some cases I've estimated probably at least 8-inch barrel to achieve box published data. We have to play all these mental games of estimating cylinder gap losses, estimating equivalency with shorter barrels, blah blah blah. Glad Buffalo Bore tested stuff in ACTUAL named firearms and published that data, but they are a small company and have expensive (and excellent) ammo. Remington has improved ammo quality, power, and function leaps and bounds lately across the board (including budget rimfire stuff), which is very nice to see.
As with so many tested cartridges by my personal observation, the culprit to function seems to be a slight lack of propellant. Thanks Dave for the video. I've enjoyed your commentary and relevancy. I also live in this highly taxed, Democrat-run state. Beautiful state, ugly politics.
