Even more inexplicable are the shooters who choose the Thor-Hammer 147-grain over the competing loads from FreedomFist and ‘MurricaHeckYeah because, according to the data on the box flap, it’s 30 fps faster at the muzzle.
I don’t mean to be the bearer of bad tidings, but those box-flap numbers come from a test barrel at the manufacturer’s facility and may or may not have much correlation with how fast a projectile is ticking along when it exits the muzzle of your own pistol.
On top of that, you have to add in the phenomenon of “extreme spread.” In a string of 10 rounds fired from the same box of ammunition, from the same magazine, in the same gun, at one sitting, even the really good, name-brand ammunition with outstanding quality control will exhibit a roughly 30 fps spread between the slowest and fastest rounds in the box.
So, if you’re choosing Brand X over Brand Y based on a 15-fps difference in the ad copy—or, worse, getting into arguments about it on the internet—you’re probably wasting your time and your keystrokes from more worthwhile pursuits, like arguing over comic books or sourdough recipes.
Not everything is empirical, especially in shooting. Whether arguments of caliber, or specific loads within a caliber, it’s important to remember the old maxim that “Shot placement is king, adequate penetration is queen and everything else is angels dancing on pin heads.”
— Tamara Keel in Splitting Frog Hairs