Home Forums Reloading Reloading Software QuickLoad propellant table & shot start pressure problem

I posted this on another forum, but didn't get any specific answer, so I'm hoping you guys can help:

I've been using QuickLOAD for a long time with great results, but I'm having a problem with shot start pressure and propellant tables.

The problem is that QL says that my subsonic IMR TrailBoss load works fine (no "Shot start pressure for this data too high" warnings). But when I create a propellant table, QL says that TrailBoss will not work. The table says "cannot find match, try to lower shot start pressure" for TrailBoss.

Am I doing something wrong, or do I misunderstand the program? Or is this a bug?

I've attached screenshots of my settings. I'm using V3.6 with a data update purchased in Jan 2015.

Dirk

Here is the TrailBoss load that QL accepts without warnings:
https://drive.google.com/open?id=0B5AgsaiWn_2OLVAtMUtjVjIxZUxnSzdXUmRXaHR0bFNlSXg4

and here is my propellant table setup that results in the "cannot find match, try to lower shot start pressure" warning for TrailBoss:
https://drive.google.com/open?id=0B5AgsaiWn_2OVXBXVzR4UHBLQ2hCbXMwZTdkRkNzcFJGcmNr

Just a hunch - maybe QLs "odd" properties (ring shape for max volume) screws up calculations?

Dirk

What case/caliber and bullet weight are you using for TB powder?

Tia,
Don

308 Win
Winchester brass
Large rifle primers

Was using 150gr Hornady FMJ-BT's, but that load wasn't very accurate. Also velocity was far lower than predicted by QuickLOAD.

I'm going to try 208gr Hornady A-Max's next to fill up more of the case, and hopefully get a more accurate load.


Dirk

Dirk

On the propellant table,
set the sliders to the slowest and fastest settings,
then exit and go to the TB powder and set the grs wanted,

I used 20grs and had No problems, using the Saami 308 caliber w/150gr FMJ bullets,showed a 124% full case.

Start pressure was set at normal setting of 3626 psi.

If you hold the pointer over/on the start pressure box, QL will show you various start pressures for the bullet types etc.

Tia,
Don

IMO Quickload is a complete waste of money. It never gives you the correct info. After weighing the capacity, checking bore ratio, proper OAL all of it will never give you the correct info. I called them about it being 300fps and 10,000psioff. They said for me to adjust the weighting factor and burn rate to match the pressure and velocity i got during testing. I said well if I have the field results already what does QL do? He said after you get it set for that certain powder it will tell you what pressure and vel it will produce by going up .1 gr.
Well crap I can load up .1 gr and pull the trigger to find that out. I've had it since 2007, used it a lot to find what general burn rate of powders will work with wildcats.
The only thing it does IMO is give you a ballpark of powders that MAY work. The velocity orpressure is never correct.

Here-Here.
Unless Hartmut did oodles of bomb testing, to get a feel for the normal burn rate variation of a powder, he's guessing to an extent. Also bomb testing gives a BR idea, which is promptly fudged once you put it in different cases, and operating pressures.

Yep.

I'll adjust burn rate for a case after I've chronographed a load. Other critical measurements are adjusted, too, such as case capacity, bullet dimensions, and some compensation for the throating. I have gotten some pretty accurate predictions once the default measurements are corrected to what I am actually dealing with. The exception to the rule is big straight walled cases.

I think the database from QL is obtained from various labs and manufacturers.