Our initial research data covered the relationship between barrel length and velocity for some 13 common handgun calibers/cartridges. In response to the phenomenal popularity of the site, we've continued to do testing, and have expanded the data to include an additional 8 handgun calibers/cartridges (and a repeat of the .380 Auto tests with ...
Barrel length and velocity is NOT a linear effect. A 44" barrel may give 2000 fps; but when shortened to 39" it may give 2078 fps. This is just an example of what can happen with any given barrel.Fast powders = shorter maximum barrel length becasue the powder burns too fast. Slower powders = ineffective in short barrel le. If the barrel is too long the pressure drops too much and the friction of the bullet in barrel will actually cause a loss of velocity!Most manufacturers quote velocities obtained from rather long barrels. For example Hornady 350 grain XTP, it quotes What velocity loss would one expect with a 4" barrel. (I realize that this is actually a 3" barrel, with 1" of compensator.)
The length of a rifle's barrel affects the velocity of the projectile. This has a significant impact on the ballistic curve. For now, I want to focus on the relationship between a rifle's barrel length and velocity. More specifically, how that relationship affects your trajectory and marksmanship.As for velocity loss, there are factory-set guidelines at differing velocities, but these seldom reflect the diverse range of calibres most shooters encounter. Each barrel's unique internal dimensions will also affect a bullet's flight, not only in terms of accuracy, but also of bullet acceleration and retardation.