by Texas Sheepdawg » Sun Sep 25, 2022 5:09 pm
Mainly the five grain difference in weight on the bullet. It’s a completely different bullet. Also, smokeless powder varies from lot to lot. Also, twist rates may be different. Barrel length may be different. All chambers are different. And most importantly, you’re shooting a bolt action where all the gas is used to propel the bullet whereas in my bench tests, I was using an AR 15 platform where the gas impingement system uses some of that pressure to cycle the bolt carrier group. This causes a small sacrifice in feet per second.
-Texas Sheepdawg
http://youtube.com/c/TexasSheepdawg21
NRA Life Member