If you want a good look at the effect of sample size, this video makes for an interesting discussion.
Nathan said:Shooting does not generate velocities randomly.
Nathan said:It is a multi variable process that we are recording velocity data from. The reason each shot differs could be dimensional differences, bullet imbalance, burn rate, bullet weight, charge weight, primer sensitivity, etc…all variables are different each shot, yet we measure velocity and group size to determine what happened!
I gave you my thoughts. I never use a load with a 10% velocity spread. I go till I get below 30fps variance. I've never used anything but Unique, Power Pistol, or 2400 for 45 Colt.Your thoughts? Am I done in 20 rounds?
GeauxTide said:I go till I get below 30fps variance.
Shadow9mm said:Hang on a sec. If I am understanding correctly, your saying Hornady has a method in which, you pick a load under max, in the velocity range you are looking for, and you just load and shoot? I cannot say as I have ever hear anyone recommend you just pick a load and shoot it. I have always been told to work a load up from start. Every gun is an individual, you might not get the velocity listed in the manual and possible different pressures. Especially if you barrel length is different from what ls listed in the manual. Also using different brass and or primers can change things. I cant say is it sounds like a good idea to me.
It's been almost 40 years since I studied statistics--so I only have random recollections and can pick out only bits and pieces from memory. I hope unclenick will weigh in with his knowledge--he clearly has a sharp command of mathematical and engineering concepts.Once you generate your “data” by random number generation, you are no longer talking about shooting. You are talking about number generation.
Shooting does not generate velocities randomly. It is a multi variable process that we are recording velocity data from. The reason each shot differs could be dimensional differences, bullet imbalance, burn rate, bullet weight, charge weight, primer sensitivity, etc…all variables are different each shot, yet we measure velocity and group size to determine what happened!
….Computer simulations are used to design and simulate tests of the US' nuclear weapons--doesn't seem far-fetched to me that they can be used as a probability tool in simulating shot dispersion.
Nathan said:…but it is unrelated to the system I’m evaluating.
You say you have a "reasonable load" of H-110.
I agree. I would likely buy 2400 or AA#9 powder if it was growing on trees around here! H110 is decent, if it builds enough pressure to burn. I agree, it would make terrible powder in a 22000psi load!I don't know what that is. H-110 is not a "reasonable load" powder. It’s a thunderhumper load powder.
One more shining opportunity: Looking at your loaded round, I see lead shaved forward and I don't see a crimp. You are not loading jacketed bullets.
You MUST bell your cases, and you MUST roll crimp into the crimp groove.
But in your Ruger, the lack of a crimp is a problem. H-110 does not light up easy. The crimp resists the bullet leaving. More heat and pressure lights the powder. The cylinder throat ? The bullet will fall through. There is no resistance. A Magnum Pistol Primer can blow the bullet forward. Then the cylinder gap lets heat and pressure escape. Forcing cone? Not till the bullet hits the rifling will H-110 get well lit if you don't crimp.
And,recoil will creep the bullets forward. See any opportunity for velocity variation?
With our home cast wheelweight bullets,bench and sandbags 100 yds,on a good day,I'd expect about 5 in groups. I'm not all that good of a shot.