Okay, so you previously didn't think powder mattered. Smitty, let me see how well I know you. The physicist in you says that pressure is pressure, velocity is velocity, and the chemical makeup and burn characteristics of the propellant that get the bullet to the end of that barrel should have zero impact on that bullet after it leaves the barrel. Is that about right?
If I think real hard, and drink a little, not necessarily in that order, I can imagine a couple of ways in which powder might impact bullet flight, but they are guesses, and I wouldn't want to voice them publicly where some unsuspecting FNG is going to read it and repeat it in some other forum in the future as fact. That said, I can tell you unequivocally that powder DOES affect bullet precision. That general fact I have no doubt about.
My clearest evidence comes from extensive testing with Montana Gold 124gr JHP, which I've shot rested at 15 yards with ten or twelve different powders inside a velocity window of 1055 - 1075. That bullet in my 75 ShadowLine made more or less the same group with every powder. And I don't mean just the same size. I mean the same dispersion. Nice and even. Super consistent. And it was, at the time, my most accurate bullet. It was the standard against which everything else was measured. And it sort of still is today. I will look at a benched group at 15 yards today, and instantly label it
bad, good, or
excellent, where my internally ingrained MG124 group is the standard for
good.
Anyway, I say it was the same with
almost every powder. It was not the same with American Select. With American Select, accuracy was downright poor. I couldn't quite wrap my head around it. This was verified on more than one day and against different loads on the same day to take me out of the equation. In my 75 Shadowline, that bullet/powder combination sucks in that velocity window. It just does. I learned to accept it. With all other bullets I tested that powder with, it was one of the most accurate powders, and with a couple of bullets at that time THE most accurate powder. I can't explain the anomaly with the MG 124JHP, but it was there. And while I haven't seen outliers of the same degree in other cases with powder alone, I have seen powders on plenty of occasions make a clear enough difference to pay attention to.
The truth is that most combinations of components that meet our basic ballistic requirements for a particular application are going to perform closely to one another, and many reloaders are looking for just good enough. They're looking for standard good. But some of use are looking for more than that. What WE are looking for, even if we've never thought about it this way, is outliers -- big fat outliers biased in our favor.
Powder is one of the components that contributes to those outliers. There's no doubt about it.
