coyotezapper
Well-Known Member
I do understand, but look at it from my point of view. Am looking for a swift load for a Magnum cartridge with high BC heavy-for-caliber bullet. If I would start somewehere around 64.0gr MRP-2, it will produce velocity approx. 2650 fps. To achieve at least 2800 fps I've to load at least 68 gr. It will make no sense if I would hit some node around 66-67 gr., it will be still slow. Thatswhy I started with 68.0 gr and worked up in 1/2 grain increments up to 70.0gr. My QL velocity calculation correlate pretty well with LabRadar measurements.
I still have some bullets so tomorrow will the story continue on the range.
Thanks for your post.
I've run the numbers in Berger's twist rate stability calculator, please, see yourself.
Click on preview for bigger pics.
After you chrono are you adjusting your QL variables to match your actual velocities? You stating you are close to QL predictions tells me no. Go back into QL and change those variables to make QL match your results 100% and then your graph will tell you where your best charge will be or close to it.
There will be several powder nodes that can be seen and correct QL inputs can help you identify these but certain inputs have to be correct. Case capacity, burn rate and temperature have to be inputted correctly for QL to work.
Even your seating depth testing has no methodology to it. The Berger website has a good article on seating depth adjustment.
Why are you testing groups at 300 yards. Again too many variables that can affect your results. If it shoots at 100 yards it will shoot at 1000 if the powder node is good.