Quickload data completely off?!?

[troller]

Hi everybody,
I know this question has been asked more than once, if QuickLoad is accurate enough or not.
Well I got finally a copy on my PC and I ran some tests comparing the official data found on Accurate website with QL simulation.
Either I have done something stupidly wrong or how do we explain these huge differences?

I mean check the images attached/below: loads are for the 500 SW Magnum:
Load 1 HDY 350 grs, 41.8 grs of AA#9, Accurate says 55.000 PSI and 1878 fps Quickload says 90.000 PSI and 2000 fps!!
Load 2 SIE 400 grs, 46.7 grs of AA5744, Accurate says 54.000 PSI and 1743 fps Quickload says 110.000 PSI and 2020 fps and also 26% of compression!

How is this possible?
I mean, OK, QuickLoad should NEVER be used to develop a Load, but at this point it makes me wonder if it has reasonable information in it at all, to compare burn%, pressures etc etc...

The data I input seems correct, all taken straight from the QL pre-set data, I just edited the COL and the Amount of powder...

Thanks
Andy

 

[colt_saa]

I think QL was designed for bottleneck rifle cartridges.

When I first got it I had to make changes from straight wall pistol cartridges.

Call QL on the phone and they will talk you through it and explain why.

I do not recall, it was too long ago

 

[rsrocket1]

Either the Accurate #9 burn characteristics are way off or the Accurate load data is way off. I tried running the numbers with the 350g XTP @1.985" SD with Hodgdon H110 against the data on their website and Quickload was very close to the Hodgdon data
10" Barrel
Hodgdon
Start load/Vel/PSI
39.0g/1,712/41,500

Quickload
39.0g/1,660/36,458

Max load
Hodgdon
43.0/1,877/50,600

Quickload
43.0/1,840/50,220

 

[ruggyh]

QL has problems with #9.

Adjust case volume by 7% and see if that helps.

Other powders seem to produce good predictions in 500 and 460 cartridges.

My H110 results are very close to simulation.

Be safe
Ruggy

 

[Nemo288]

Long QuickLOAD ramble. Have fun.

Read ALL the tutorials and white papers that come with QuickLOAD.
It is most accurate with necked cartridges ~60 kpsi.
It gets less accurate as you go to cylinders and even less accurate as the pressure goes down.
The best way to use QuickLOAD is to provide it with feedback from actual chronographing.
Adjust the case capacity and possibly the powder burn rate SLOWLY until the results match your reality as measured.
Also play around with the "weighting factor" and the shot start pressure (a measure of the initial friction).
Then make a prediction (something under max pressure).
Manufacture that load and then compare it to the prediction.
The more you work with a certain cartridge and power combination the more accurate and confident you become about predicting new combinations.
Some powders have fairly large errors in the bulk density department and there is no good way to adjust this.
The density parameter in the powder window is NOT the bulk density.
You will learn how to interpret the loading density as you use the program and then look at your powder column before inserting the bullet.
There is a fairly steep learning curve but it is a fascinating program and playing with it is the best way to make it more and more useful.
I find that with revolver and straight rifle rounds the results are fairly conservative.
But dont take my word for it as your results with different cartridges may be different as well.
When the program results match your measured velocities especially for more than one powder charge weight,
then you can start to believe the calculated pressure a little more.
Good luck, have fun and stay safe!

Here is one example where I have changed the powder burn rate and case capacity and gotten very close
to measured velocities all along the higher end of this cartridge.
It is in fact a duplication of both Hornady factory loads.
I now go ahead and use this powder profile with other bullets in this cartridge.

Addendum:
It may seem counterintuitive to have to measure velocities in order to have a program then predict them.
This goes hand in hand with the fact this is not a reloading program.
Your reloads, as far as possible should be coming out of a reloading manual.
Where it does shine is: suppose I want to make a 44 Alaskan.
There is no loading data because there is no such cartridge.
There are a couple that are close.
You define the cartridge brass dimensions.
The program does a nice job of figuring out the case capacity from this.
Then you can use the program to figure out what powders might be useful.
Pick one on the slower side that fills up the case.
Now you can start thinking of how to pay for a custom rifle, dies and brass.
I haven't gotten past this last step.

Edit:
You will find the parameter that changes pressure the most is bullet seating depth.
Minor changes in usable case capacity can effect the pressure radically.
These figures must be correct to the .001".
Move the bullet up and down and you will see what I mean.

 

[BLUEDOT37]

QuickLoad

You will find the parameter that changes pressure the most is bullet seating depth.
Minor changes in usable case capacity can effect the pressure radically.
These figures must be correct to the .001".
Move the bullet up and down and you will see what I mean.

.

I noticed QL seating depth for both bullets was deeper than what I recorded when I loaded those same bullets.

QL seating depth: Sierra 400gr JHP = .435"; mine measured .422"

QL seating depth: HDY XTP 350gr JHP = .411"; mine measured .390"

Wonder how much difference those reading would make?

.

 

[Nemo288]

I noticed QL seating depth for both bullets was deeper than what I recorded when I loaded those same bullets.
Wonder how much difference those reading would make?

A lot.
You need to set those figures as they really are, not what comes out of the machine by default.
If you have the right bullet, the seating depth will be calculated from the COAL.
The bullet lengths are usually correct in the program (doesn't hurt to measure them anyway).
Just measure your COAL and enter it.

As you are finding out, there are a LOT of numbers involved.
If a bullet is not on their list (like the 276 grain Radioactive), you can define new ones as well as new cartridges.
You will see how picky they are about these definitions although their forms make it pretty easy.
If you find a small error with one of their bullets (I have), you can correct these.
I suppose you could define a new powder but that would be way beyond my ability.

If you get bored, grab a drink and model something like this 5.7 Xpress:
Looks to be something like a 22-20mm.