There are many considerations when it comes to barrels and accuracy/ precision, but length is not one of them. This is actually a fable, and one that is commonly seen and heard amongst the shooting community.

Does Length really matter? Yes it does, when it comes to velocity, but not accuracy. These do not go hand in hand. Velocity does not equal accuracy, but velocity is a major contributor to external ballistics which includes terminal ballistics. This is why it is critical to match the cartridge and rifle setup to the intended purpose(s).

The illusion is the longer the barrel the more accurate the gun is. This is far from being correct. With a shorter barrel you will lose some velocity, but as long as you have the appropriate amount of velocity for the construction of the bullet and energy for the engagement distance, you will be able to dispatch game or hit your target just as effectively as you could with a longer barrel.

Two contributing factors to accuracy when the cartridge is fired are barrel harmonics and barrel whip. Both of which are affected by barrel length and rigidity. These two elements are why barrels will typically have both a low and high velocity accuracy node. In essence, a barrel is like a tuning fork. One way to reduce the effects of harmonics and whip is to use a barrel that is more rigid. I.E. larger diameter and/ or shorter in length. As a barrel becomes longer, an increase in barrel whip can be seen using high speed cameras when the rifle is fired. To reduce the weight of longer barrels it is common to see smaller barrel profiles as well as fluting. While barrel fluting can induce its own accuracy concerns, reducing the profile of a longer barrel generally reduces its rigidity while increasing barrel whip.

So let’s look at some numbers from a couple of 6 ARC’s that were using the same barrel, but in different lengths. When fired across a chronograph I was finding that a 22″ barrel with a handloaded 58g Hornady V-Max was averaging a velocity of 3367fps without a suppressor. Using the same load, on the same day, and under weather conditions that did not change much I found that the 20” barrel would only achieve an average velocity of 3326fps without a suppressor.

With a loss of velocity we must account for bullet drop at intermediate to longer distances. The amount of compensation is very dependent upon the cartridge and load being fired, as well as the atmospheric conditions that are present, but this can be achieved by using holdovers or by dialing elevation on your optic. This compensation though does not affect one’s ability to be accurate if the correct allowance is dialed in. Let’s look at the 6 ARC again. With a 22″ barrel running a 58g V-Max bullet at 3367fps and utilizing a 100yd zero, the bullet drop is 3.13 MOA (.91 Mil) at 300yds. That same combination out of a 20” barrel results in a bullet drop of 3.24 MOA (.94 Mils) with the same zero. Yet both rifles consistently shoot .3 to .5 MOA groups.

So what are the pros of a shorter barrel?

• Lighter rifle
• Better maneuverability- especially with a suppressor
• Quicker on target or when transitioning targets
• Typically a better balance point on the rifle
• Barrels are more ridged than their longer versions
• Easier to store and transport

What are some cons of a shorter barrel?

• Reduced velocity and energy at further distances- Especially over-bore capacity cartridges
• Shorter gas system lengths and reduced dwell time
• Increased muzzle blast can be a concern- Especially over-bore capacity cartridges
• Heat dissipation can be of concern
• Lighter weight and may have more recoil- Dependent upon a lot of factors

What it comes down to is this…. What’s the purpose of the rifle? What’s the rifle chambered in? What engagement distances are we looking at? What do we need the rifle to do as far as ballistics go? With all of that said, my choice of barrel length for predator hunting is 20” for most cartridges in the AR platform. The typical engagement distances in my area are 300 yards or less, but occasionally shots at 400 or so yards will occur. The velocity and energy produced by most cartridges in this barrel length is more than effective on predators at intermediate ranges. 

BRD Gun Works LLC~ Performance on Demand