Working up loads like you are is a great way to find flat spot to load to, and sometimes when you get to a flat spot in the speed/ pressure you can see higher charges go slower than the one before it but thats usually no more than 5-10 FPS. It may verily be your chrono if it’s bad errors before. I’d suggest trying to find a magneto speed v3 or a lab radar to barrow.

P.s. I hate cleaning and am usually pretty lazy with it too lol.