That sort of testing is less valuable than most people think. If you want to know pressure in your rifle, you have to test with a strain gauge on your rifle. Differences in chamber, bore and throat geometry are some of the largest non-mistake-related sources of velocity and pressure variance.
The right way to use quick load is to know that it's sometime (slightly) wrong about the load, just like reloading manuals. But it's essentially never wrong about the relationship between pressure and velocity. If you load to the velocity it says you will get after setting all relevant parameters, you will be VERY close to the pressure it says, regardless of what the charge weight ends up being.
In years of using QL for wildcat and obsolete cartridges with a strain gauge, I have never seen it be seriously wrong on a bottleneck rifle cartridge, and when it's slightly wrong it's almost always conservative as it assumes you have a min spec chamber but that's not likely true. Straight wall rifle is fine too if you read the manual and make the required corrections. I have seen far more gross errors in commercial load data and various loading books and magazines.
