Ruger American in 6.5 Grendel

[LRRPF52]

I think the velocity loss for Grendel is around 25-30 fps per inch IIRC. There is a chart in the Grendel handbook from Paul. This is the reason for the popularity of the 16-18” pipes over the 22-24”. Even the 12.5” Grendel’s are holding their own out to medium range.

http://www.65grendel.com/forum/showthrea...d-Velocity

ETA: Found the old chart from years ago

Joe made that chart. Barrel loss per inch is not a linear function, since you have different curves based on the optimum length for the case capacity, working pressure, and projectile shape/weight with given bore volumes.

I did a science project focusing on barrel length with the 6.5 Grendel and found something like 18fps per inch difference between various 16" and 20" rifles shooting the same loads, so roughly 76fps mv difference between a 16" and a 20".