12-12-2023, 04:24 AM
Jasper,
I am not offended, but I am concerned you are providing damning advice about using a program which many others use without issue. Your associated advice about particular loads for Scrape are not the issue.
I find it hard to believe your QL (Quickload, unsure why you use the acronym 'QT', what does T stand for?) has a default 37.5gn water capacity as it is public knowledge that it is 35. An extra 1-2 gns of capacity makes a lot of difference to predicted pressures when loading compressed and on the raggedy edge. Less so if the load is not compressed and conservative. With respect, are you sure you didn't change the capacity while tinkering and unwittinglly locked it in?
I have four Grendel calibres on the pull down menu: two came with the program and two are for my cases. This is for when I am calculating loads for fresh/unfired brass, or fire-formed spent/sized cases. There are subtle differences in the predictions with typically 0.1gn difference when looking at max charges. Also, instead of entering 18" for a Lilja I enter 18.8" which is the actual measured length of the barrel. So GIGO at play here, the more precise the inputs, the more useful the outputs.
I think we all agree...QL will never be exact, and those expecting this are fooling themselves as to what a computer simulation of a gun firing can do. How energetic powder is varies from batch to batch, and also influenced by the ambient temperature - Winter or Summer. You can sort of enter this by enabling the powder data fields and adjusting, but it goes down the rabbit hole of guessing physical data without a laboratory. I have not explored the program to this level of detail but just know loads developed in Winter need to be reconsidered for Summer. Others say the short case confounds QL by primers launching the bullet and temporarily increasing the 'case capacity' before the powder train has burns. For me, knowing how conservative it is and coupling this with manufacturer tables gives the overview I need to maximise internal ballistic efficiency, while not breaking the gun.
I really think you should measure your own case volumes and go with that, regardless of what the QL programmers gave it as a default. There will be a difference.
I am not offended, but I am concerned you are providing damning advice about using a program which many others use without issue. Your associated advice about particular loads for Scrape are not the issue.
I find it hard to believe your QL (Quickload, unsure why you use the acronym 'QT', what does T stand for?) has a default 37.5gn water capacity as it is public knowledge that it is 35. An extra 1-2 gns of capacity makes a lot of difference to predicted pressures when loading compressed and on the raggedy edge. Less so if the load is not compressed and conservative. With respect, are you sure you didn't change the capacity while tinkering and unwittinglly locked it in?
I have four Grendel calibres on the pull down menu: two came with the program and two are for my cases. This is for when I am calculating loads for fresh/unfired brass, or fire-formed spent/sized cases. There are subtle differences in the predictions with typically 0.1gn difference when looking at max charges. Also, instead of entering 18" for a Lilja I enter 18.8" which is the actual measured length of the barrel. So GIGO at play here, the more precise the inputs, the more useful the outputs.
I think we all agree...QL will never be exact, and those expecting this are fooling themselves as to what a computer simulation of a gun firing can do. How energetic powder is varies from batch to batch, and also influenced by the ambient temperature - Winter or Summer. You can sort of enter this by enabling the powder data fields and adjusting, but it goes down the rabbit hole of guessing physical data without a laboratory. I have not explored the program to this level of detail but just know loads developed in Winter need to be reconsidered for Summer. Others say the short case confounds QL by primers launching the bullet and temporarily increasing the 'case capacity' before the powder train has burns. For me, knowing how conservative it is and coupling this with manufacturer tables gives the overview I need to maximise internal ballistic efficiency, while not breaking the gun.
I really think you should measure your own case volumes and go with that, regardless of what the QL programmers gave it as a default. There will be a difference.