Bobarian
Member
I'm still fairly new to handloading. Because I'm a technogeek, I need to see the numbers, so I got the Shooting Chrony Alpha.
Learning how to use the chrony, I fired ten rounds of American Eagle 115 gr 9mm FACTORY ammo over this thing with my S&W Shield. Muzzle was about 8 feet or so from the unit. (The instructions are a little vague WRT distance from the unit for handguns.) The average velocity for the ten rounds was 1394 fps.
My question is: Why are the velocities I'm seeing with factory rounds so much higher than what the reloading tables indicate? The highest velocity on Hornady's 115 gr table is 1250 fps.
Muzzle blast? Am I just too close? Seems like the readings would be more erratic if that was the case (extreme spread was only 12 fps).
Learning how to use the chrony, I fired ten rounds of American Eagle 115 gr 9mm FACTORY ammo over this thing with my S&W Shield. Muzzle was about 8 feet or so from the unit. (The instructions are a little vague WRT distance from the unit for handguns.) The average velocity for the ten rounds was 1394 fps.
My question is: Why are the velocities I'm seeing with factory rounds so much higher than what the reloading tables indicate? The highest velocity on Hornady's 115 gr table is 1250 fps.
Muzzle blast? Am I just too close? Seems like the readings would be more erratic if that was the case (extreme spread was only 12 fps).