Ladder testing.

[mram10]

I assumed a true ladder test. The last rums I worked up a load with 215s I used a 3x4 piece of craft paper at 500. Used 96-102gr of r33 in 1 gr increments. Narrowed the nodes to 99-101 in .5 gr increments. Reshot at 1000 and found the sweet spot. Need to narrow a bit more for the heck of it.
Did the same with 225 eldm. Picky as it only allowed a .2 gr node for best accuracy.

 

[Bart B.]

i do not know how you can justify velocity equals excess pressure.
bbls are different, primers are diff, temp elevation humidity all different than book listed data.

i have several bbl that exceed expectations with NO pressure issues.
while velocity and pressure are related it is tuff to pick a point and say"that is excess velocity" without
a pressure transducer on the chamber.

Assessing pressure by visual inspection of case and primer is usually misleading.

Having shot dozens of 7.62 NATO proof loads, most folks thought the fired cases looked pretty normal for a maximum load. The cases had about 68,000 cup (83,000 psi) peak pressure. I agreed; they did look OK.