How .308 Win Velocity Changes with Barrel Cut from 28″ to 16.5″

By Editor

With barrels, one wonders “Can a little more length provide a meaningful velocity gain?” To answer that question, Rifleshooter.com performed an interesting test, cutting a .308 Win barrel from 28″ all the way down to 16.5″. The cuts were made in one-inch intervals with a rotary saw. At each cut length, velocity was measured with a Magnetospeed chronograph. To make the test even more interesting, four different types of .308 Win factory ammunition were chronographed at each barrel length.
This is a very useful test is you’re thinking about building a .308 Win hunting rifle, or perhaps thinking of going shorter for your F-TR rifle to save weight.

READ RifleShooter.com .308 Win Barrel Cut-Down Test Article.
Test Barrel Lost 22.7 FPS Per Inch (.308 Win Chambering)
How much velocity do you think was lost, on average, for each 1″ reduction in barrel length? The answer may surprise you. With a barrel reduction from 28″ to 16.5″, the average speed loss of the four types of .308 ammo was 261 fps total. That works out to an average loss of 22.7 fps per inch. This chart shows velocity changes for all four ammo varieties:

Summary of Findings:
The average velocity loss per inch, for all four ammo

Source: Accurate Shooter