Ammunition & Hand Loading > Cartridge and Shotshell reloading
Aldo's .45 ACP formula
JimP:
Aldo, I have a Chrony....... not a real spendy Chronograph, but it works. I would be happy to bring it to a meet and greet when we have another one.
Extreme Spread (ES) is the difference between the highest velocity and lowest velocity recorded in the string of shots.
Standard Deviation (SD) is the measure of dispersion of data points in a data set- in this case, velocities- basically, how close to the mean (average) velocity most of the velocities are.
Both ES and SD measure how consistent your loads are....... which is extremely important for benchrest type accuracy, but not so much for punching cardboard/ plinking ....... unless you are playing around the minimum or maximum charge levels..........
Most load/gun combinations have a "sweet spot" where the the SD (and group) will stay small ....... at least that has been my experience.
Aldo:
Hey, JimP, sounds great to me!
It's obvious I don't know that part of the equation of what I am doing with my reloads, and I appreciate the offer! It would be good to test out what I am doing with more objectivity than what I am now doing with just target shooting.
Now here's a dumb question on my part: when testing my .45s, wouldn't I need to have them braced in a vice to eliminate the human element of hand-holding, moving the handgun when squeezing the trigger, etc?
Next dumb question: using my digital scale, would I want to group my loads so that they are in exact same weight groups, especially since my overall weight of the reloads range from 321.4-323.8, or is that getting too nitpicky (is that a word)?
One more dumb question: my reload manual gives me the max amount of powder limit, but it does not give me the min amount, and I can't find that anywhere on the net for the powder I use. Ideas?
Thanks again to offer re the chronograph testing of my reloads. Right now the only meets I go to are Rock Your Glock at Ike's. Perhaps at the end of one of those meets???
Randy:
Quoted from Aldo
"Now here's a dumb question on my part: when testing my .45s, wouldn't I need to have them braced in a vice to eliminate the human element of hand-holding, moving the handgun when squeezing the trigger, etc?"
First there are no dumb questions.
The Chronograph will only have minute variations if any from not using a gun vise. I have one but due not use it when testing my re-loads. More important is that you keep the same distance from the Chronograph sensing rods.
"Next dumb question: using my digital scale, would I want to group my loads so that they are in exact same weight groups, especially since my overall weight of the reloads range from 321.4-323.8, or is that getting too nit picky (is that a word)?"
Yes nitpicky :adj Definition: overly critical, esp. on trivial matters;
focused on only trivial aspects
This depends how much time you have, by sorting bullet weight, brass brand and weight you will have more consistency in your reloads both inaccuracy and in velocity. Very time consuming. If you want Match Grade bullets than purchase them they will have the least amount of bullet weight deviation and do cost more.
"One more dumb question: my reload manual gives me the max amount of powder limit, but it does not give me the min amount, and I can't find that anywhere on the net for the powder I use. Ideas?"
Minimum powder charge weight is 10% less weight than the maximum safe weight amount.
Here is one good web site. http://www.hodgdon.com/
With information on three different powder brands, powder burn rates, bullet weight and charge weights.
Aldo:
Hey, Randy. Greatly appreciate the responses! :)
1) Good to know about not having to use a vise.
2) I already sort my reloads by brass brand, bullet brand, but not by overall weight. For the testing, though, I don't mind putting in the time since JimP is game on spending the time with his chronograph.
3) Good to know that 10% rule to use re the min powder limit. With 5.0 being my max listed in the manual, seems like I am in the ok window by using 4.6. Thanks also for that website!
Randy:
Jim P, will not steer you wrong. Good man.
Also you are welcome.
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