Velocity loss on shorter barrels

[TheM4chef]

Hi guys I'm curious I finally got a chance to use my magnetospeed on my 20" 223 AR15 I was getting a average of 2743 fps

My question is my mk18 has its flash hider flush on the 10.3" bbl with the hand guard so I can't get accurate readings. Is there a reliable fps loss per inch I can calculate on?

 

[yodave]

25 FPS per inch is the rule of thumb, if you can shoot beyond 100 yards at know distance you maybe able to confirm your findings with the bullet drop

 

[todbartell]

get a Labradar doppler radar

I shot a factory load between my 22.4" Tikka and 16.1" Ruger 223, 27.5fps per inch

 

[MRP]

Good reference here.

http://www.ballisticsbytheinch.com/223rifle.html

 

[Ganderite]