Loaded up 5 identical rounds using the following method/equipment: sorted weight brass to within .3g; powder weight on a RCBS 10-10 scale; seated bullets with a Co-Ax press and RCBS comp dies. Shot these five rounds, recorded results and shot the next 5 rounds with a powder charge increase of .3g. Took a 5 minute break after 20 shots to let the barrel cool. 70 degree temperature, no wind, sunny and little to no clouds and 25% humidity.
Ran all shots thru a Pact Model 1 XP Chronograph (brand new 9-volt battery) at a distance of 10 year from the barrel. Let’s see if I can make sense of these questions: #1- how much effect does the rifle have on SD/ES? #2– if all rounds are identically loaded, shouldn’t the recorded velocity be within say 2%? #3– If I took a full box of factory ammo what kind of % spread would be considered normal?
Ran all shots thru a Pact Model 1 XP Chronograph (brand new 9-volt battery) at a distance of 10 year from the barrel. Let’s see if I can make sense of these questions: #1- how much effect does the rifle have on SD/ES? #2– if all rounds are identically loaded, shouldn’t the recorded velocity be within say 2%? #3– If I took a full box of factory ammo what kind of % spread would be considered normal?
