QuickLoad alternatives?

[spacecoast]

Does anyone know of reliable internal ballistics software that is free or not as pricey as QuickLoad? I only need it for evaluating a few common pistol cartridge, bullet and powder combinations.

[Brian Pfleuger]

The Firing Line Forum, subforum: Handloading and Reloading.

[steve4102]

You can check out "Load From a Disk" it's similar and about 1/2 price. I have both, I like QL and think LFD is very limited, hence the price.

[SL1]

with Homer Powley's equations that you can probably get free or cheap and program into a computer yourself.

I did that back in the 1980s when personal computers became widely available. Almost all of the currently available commercial computer programs for handloaders use those same equations. But, they needed to add some information and extrapolate the cartridge configurations from Powley's work, because those original correlations were only for IMR powders in bottleneck rifle cartridges. One indicator that this is what is being done in a commercial program is the "lumping" of multiple powders together with the same charge weight results. A quick look at any real pressure-tested data will convince you that these types of programs are NOT particularly accurate with respect to charge weight vs pressure relationships.

QuickLOAD is different, in that it uses data for each specific powder that was derived by testing one or more lots of that powder, and then it does a numerical simulation of the buring process in the case of your choice with the powder of your choice in the barrel of your choice. QuickLOAD provides more informative out puts, such as % of powder burned as the bullet moves down the barrel, and a lot more. It also gives you data for several powders that are now revealed as "identical" such as H-110 and W-296, so that you can see how different the results can be when changing what amounts to the lot number for a specific powder. It is a LOT more educational than the other programs.

But, you DID say "reliable", and that is beyond ALL currently available software. Even with QuickLOAD, it is easy to get results that are not very realistic. You need to learn how to use it properly, and what its limitations are. Essentially, I try to "tune" it to a specific cartridge using pressure test data for that cartridge from a load manual. If I can't match the data, I don't trust the program for that cartridge or powder or whatever isn't matching. There are a LOT of reasons for sometimes not getting a match.

So, whatever you decide to do, please don't assume it is "right" because it came out of your computer.

But, I DO think it is worthwhile to learn what these programs have to offer us in the way of better understanding of the underlying relationships of the parameters that we manipulate as we handload.

The publication that I used for Powley's correlations many years ago was an article by Wm. C. Davis, Jr., titled "Some Simplified Interior Ballistics for Handloaders" in an NRA publication titled "Handloading" that is copyrighted 1981. I don't know if it is still available from the NRA.

SL1

[Unclenick]

Unfortunately the NRA book is long gone. I should probably scan the Davis article from my copy for interested people, but don't know what the copyright ramifications are? I'll have to call the NRA to ask what their policy is? A lot of the old NRA technical stuff has dried up, probably because of liability considerations. You used to be able to buy past Rifleman articles on things like doing trigger work on common match guns, but they've stopped making them available to buy.

A Ballistics Handbook, by Scottish ballistician Geoffry Kolbe (ISBN 0-9537537-0-0), has a run down of the Powley calculations, too, with some examples.

Load from a Disk uses the Powley calculators, but that means it likely works best with IMR powders and only wants to work with a narrow range of case fill. Check their FAQ online. One question in the FAQ asked whether you can put your own powders in? The answer is no, and the related limitations are listed thereafter. QuickLOAD will let you create your own powder, but you really need to know what you are doing to make that work well. It's not the first thing you should undertake to do.

[spacecoast]

Unclenick -

Thanks very much for the detailed info. I found a program called WinLoad by John Knight in the UK - http://www.stickledown.co.uk/ - that does say that it's based on the algorithms developed by Powley. I downloaded it and tried it, but as you say it looks like it's only applicable to a narrow range of cases for IMR powders.

As I would like to understand the relationships better between the parameters (making small changes in established loads) it looks as if QuickLoad is going to be the way to go.

[Unclenick]

The Kolbe book quotes Homer Powley:

"First contemplation of the problems of Interior Ballistics gives the impression that they should yield rather easily to relatively simple methods of analysis. Further study shows the subject to be of almost unbelievable complexity."

So it goes. QuickLOAD has so many arguments to tweak that it quickly teaches you quite a bit about the factors involved, and tweaking them reveals the relationships and their relative influence. Powley tried to simplify it for amateur level work with a slide rule system, but this was before personal computers were available to do mathematical heavy lifting, which is why his simplifications were forced to have limited scope.

[SL1]

If you get permission (or just decide) to post the Davis article, would you check the equation on page 142 for velocity?

It reads:

V = 8000 x SQR(I - N / Y)

but, some time in the past, I made a note to myself that I thought it should be

V = 8000 x SQR(I x N / Y)

Thanks.

SL1

[Unclenick]

I'll have to look. Kolbe gives Powley's equation without so many pre-figured terms as Davis uses as:



Where:

L = Powder Weight in Grains
G = Bullet Weight in Grains
r = Expansion Ratio

Looking at the lower form, a subtraction is involved. So we'll have to look at Davis's terms I, N, and Y to see if they match up?

That equation reveals one of the limitations of the Powley's simplified approach. Powder weight in a velocity equation only works if all the powders you are using have the same energy content per grain. The IMR single-base rifle powders are certainly close to one another, but there are other powders which are not.

You also have to assume the burning gets pretty well done by bullet exit from the barrel. Kolbe has a graph of measured velocity verses that calculated by the Powley equation. For a .30-06 load in the example, they don't agree well except at zero and from about 16" of barrel forward. For a slower powder, presumably the barrel has to be still longer before agreement is good. 5% seems to be the equation's accuracy limit, but Kolbe points out that all the other factors of barrel friction, chamber size, primer choice and so on, can change velocity 5% anyway. So, he feels the equation is good enough at 5% precision for application to an unknown gun.