Rifles come in all shapes an sizes from lightweight mountain rifles to heavy F-class target guns. Just like the rifles they come on, barrels come in different profiles, materials, and lengths. Quality barrel selection is the most consistent way to get a rifle to shoot well. Consider this a breakdown of the basics in understanding the tradeoffs between different types of barrels.
Barrel Length
First of all, the most obvious difference between different barrels is the length. Contrary to popular opinion, longer barrels are not more accurate. Instead, it is the quality of the barrel itself that determines accuracy. What the length of the barrel does affect is the velocity of the cartridge. A longer barrel gives the gun powder time to completely burn and impart the maximum amount of energy into the bullet. Longer barrels result in higher velocities and flatter trajectories. On the other hand, long barrels are also heavier and make the rifle longer and less ‘handy’.
So how long of a barrel should you choose? That depends on your cartridge and the area you intend to be hunting in. Some cartridges with fast burning powders don’t need a very long barrel in order to completely burn all of the powder. For example, a 22LR can completely burn all of its powder in a 16 inch barrel. On the other hand, a large magnum may need 24 or 26 inches of barrel for its slow burning powder to completely combust. Ballistics By the Inch has an incredible library of cartridges showing how barrel length affects velocity.
The other factor is where you plan to hunt. If you are planning on hunting in dense cover, shots tend to be short and handiness is more important. In that case, ballistic loss from a shorter than optimal barrel may be acceptable in order to improve handiness. However, a general rule of thumb is most standard hunting cartridges require at least a 22 inch barrel and most magnums require at least a 24 inch barrel to reach their full potential.
Barrel Profile
Next, barrels also have a wide range of profiles. There are heavy bull barrels to pencil barrels and everything in between. Heavier barrels convey a multitude of benefits. First of all, they heat up more slowly. This makes them much more consistent during longer strings of fire where four or more shots are being fired. Keep in mind that when heavy barrels do get hot though, they also cool more slowly.
Another advantage of heavy barrels is they are more rigid. This tends to make heavy barrels more forgiving as far as finding ammunition that they will shoot well. Pencil barrels can also be incredibly accurate, but tend to require more tuning than a heavy target barrel would. Each barrel is an individual, but in general a heavy barrel profile is less picky than a lighter counterpart.
However, heavy barrels still have one significant drawback. They get very heavy very fast. This isn’t an issue for a dedicated range gun or even a gun that lives most of its life in a tree stand. However, in a western hunting scenario where rounds shot are few and miles walked are many, the benefits of a heavier barrel are not worth the weight.
Twist Rate
Twist rate is something to consider if you are buying a barrel as a component instead of as a part of your rifle. Historically, manufacturers wanted to spin a bullet fast enough to stabilize it, but not so fast that it breaks apart. Nowadays we are discovering that it is very difficult to overspin a bullet, but quite easy to underspin it.
So why is spin important? New, cutting-edge bullets are heavier and sleeker than older designs. The longer a bullet becomes, the faster the twist rate needed to stabilize it. Faster twist rates let the barrel handle heavier-for-caliber bullets without any practical downside. These heavier bullets have higher BC’s which makes them easier to shoot at long distances.
Barrel Finishes
There are many different finishes that can be applied to a barrel. While most of them don’t affect accuracy, there are a few that I would like to touch on briefly to explain the pros and cons.
Barrel Fluting
Fluted barrels are available on a number of higher end rifles. The fluting removes weight while maintaining the rigidity of a heavier profile barrel. However, it does introduce another variable in the barrel, so it potentially could have a slight negative impact on accuracy. More significantly, the fluted version of a barrel will be more expensive than the standard barrel.
Carbon Fiber Wrapped
Another barrel finish is carbon wrapped barrels. Wrapping a barrel in carbon fiber gives it the rigidity of a thicker barrel profile but is much lighter. This is a very attractive combination for dedicated backcountry hunters. The main drawback of the carbon fiber barrels is the cost. Carbon fiber barrels typically cost up to twice as much as a standard steel barrel.
Chrome Lined Bores
Many older rifles, particularly military surplus arms have chrome lined barrels. This was originally done to help the rifles resist corrosion from old corrosive military ammunition. The chrome lining process makes the bore more durable but accuracy will suffer. For military purposes this is fine however, for a hunting rifle, this should be avoided.
Closing Thoughts
In closing, picking a the right barrel is an integral part in picking the right rifle. There are always tradeoffs, usually to do with the weight of a rifle. Careful consideration on your cartridge and common hunting conditions will help you pick the right combination. I would recommend picking a target weight for your purpose and then working backwards fro their to pick the perfect barrel for the task at hand.