QL is a non starter with out an accurate chronograph, however, models can be produced to give a general idea of what components would be ideal for your application.
QuickLoad vs Chronographed Velocities: Effect of Shot Start Initialization Pressure
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QL is a non starter with out an accurate chronograph, however, models can be produced to give a general idea of what components would be ideal for your application.
Without actual chronograph/radar velocity from your rifle to tune QL to match your result, QL is just a useful tool for comparing different powder predictions.
I tried this out in GRT. If I use the 10825 psi minus 27psi/0.001" jump, I have to lower the burn rate (Ba) of Varget by just over 14%. The adjusted burn rate is closer to the H4350 model than it is the Varget model. Are you changing any other parameters to calibrate the model to your measured velocity? I should note that the resulting modeled pressure is only about 400psi different and both models closely resemble actual velocities across a range of charge weights.
It doesn't seem reasonable to me to change the burn characteristics of powder models so much that they resemble drastically slower burning powders in order to accommodate that higher start pressure. I'm genuinely interested on how others manipulate these models. I don't insist that how I do it is the best way, so the more knowledge I can compound the better.
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Few people realize that Quickload is not Pressure Testing Equipment, but software that provides estimates based on an excellent, yet imperfect model.
It's absurd that there would discussions about using inputs like 10,825 and 3625 (rounded to five) when in practice Quickload is accurate to perhaps 5-10% of what you will actually obtain, so on a pressure of 50K, thats +/- 2500-5000 psi, making a number like 5 meaningless.
I would rank pressure equipment as follows:
1 - actual pressure testing equipment - accurate to perhaps 1%. Of course if you conduct the test on the "exact same" ammo again, it will differ, particularly in a different barrel;
2 - a Chronograph. See above but it's for MV not pressure, although there is a relationship between the two;
3 - bullet drop at 300-1000 yds. If you know the BC of the bullet and the atmospheric conditions, you get a pretty good estimate of MV; and
4 - Quickload, which I have and use to do initial work on loads.
Just some perspective.
QL gives a max pressure, how accurate that is ,I have no way of telling at face value.
A given charge weight will give a velocity in your rifle and components.
This velocity, the acceleration rate of the bullet in the bore, will get you a barrel time.
In a 20" bbl there are a few barrel times that coincide with an OBT, these are 0.9237 and 1.0257 mS, being useable.
The powder charge , once the Ba is reconciled , will put bullet exit on an OBT.
I've had good result doing it that way.
A given charge weight will give a velocity in your rifle and components.
This velocity, the acceleration rate of the bullet in the bore, will get you a barrel time.
In a 20" bbl there are a few barrel times that coincide with an OBT, these are 0.9237 and 1.0257 mS, being useable.
The powder charge , once the Ba is reconciled , will put bullet exit on an OBT.
I've had good result doing it that way.
