When I got my first look at the 6.5 Creedmoor when it came out in 2007, I, like many gun enthusiasts, wondered if I could shoot it in my .308 rifle. They looked similar, and though .308 ammunition won’t fit in a firearm chambered for 6.5 Creedmoor, the reverse worked. So did that mean I could shoot 6.5 Creedmoor in a .308 rifle?
You cannot shoot a 6.5 Creedmoor in a .308 rifle or vice versa. Trying to do so could damage the firearm or injure you. These dangers primarily result from differences in case dimensions and chamber pressure that will at least lead to a loss of functionality.
Since I was a teenager when it came out, I naturally had to try the 6.5 Creedmoor in my dad’s .308 Winchester. Now I’m here to explain the differences between the cartridges and the consequences of their incompatibility. Keep reading to learn more.
Potential Dangers of Using 6.5 Creedmoor in a .308 Rifle
There are several reasons why a 6.5 Creedmoor cartridge should never be used in a .308 rifle. Take note of the following dangers.
Extraction Issues and Misfires
Since the 6.5 Creedmoor has a shorter case length than the .308 Winchester, it may not fit correctly in a .308 chamber. This could lead to extraction issues, misfires, and other malfunctions that can affect your safety and your rifle’s functionality.
Inappropriate Chamber Pressure
Because a 6.5 Creedmoor cartridge doesn’t usually fill up the chamber of a .308 Winchester rifle, it won’t form a seal at the throat. This will likely result in inappropriate pressure that will cause the bullet to travel incorrectly down the barrel.
At best, the rifle will fire like a smoothbore musket with no reliable accuracy. Luckily this was the worst that happened to me when I tried it. At worst, though, you will tear up your gun’s rifling and permanently hinder its accuracy.
Damage to the Rifle
If you put a 6.5 Creedmoor in a .308 rifle, you risk damaging it. The most likely damage is to the barrel and rifling, but you may also hurt the chamber, bolt, or action.
Even worse, if the gun misfires or has another dangerous mishap, it could also injure you. For all these reasons, it’s best not to try it.
Alternatives to Using 6.5 Creedmoor in a 308 Rifle
If you’re interested in using 6.5 Creedmoor and .308 Winchester cartridges, there are a few alternatives instead of attempting this potentially dangerous action.
Interchangeable Barrel Systems
Some rifles are designed with interchangeable barrel systems that allow you to swap between calibers easily. Get a rifle with this feature, and you can safely and effectively use the 6.5 Creedmoor and .308 Winchester without getting separate guns.
Some rifle manufacturers offer caliber conversion kits that allow you to modify your existing rifle to accept a different caliber. These kits typically include a new barrel, bolt, and magazine components specific to the new caliber.
Before considering this option, ensure the conversion kit is compatible with your rifle and legal in your jurisdiction.
Separate Rifles for Each Caliber
Of course, another option is to get another rifle chambered for 6.5 Creedmoor. Then you can use the appropriate ammunition for each rifle without worrying about compatibility.
It will also save you the hassle of dealing with conversion kits or swapping out the barrels of a single gun.
Overviews of the 6.5 Creedmoor and .308 Winchester Cartridges
Now, let’s take a look at the characteristics of each cartridge.
The 6.5 Creedmoor is a relatively new cartridge introduced in 2007 by Hornady and designed for long-range shooting and hunting. It uses a .264 caliber (6.5mm) bullet.
People like the 6.5 Creedmoor for long-range target shooting and hunting because it produces less recoil and has a flatter trajectory at longer ranges. It offers excellent ballistic performance, particularly in high-wind conditions. This is ideal for hunting, particularly out west.
Winchester introduced their .308 cartridge in 1952. Since then, it’s become one of the most popular types of ammunition for hunting, target shooting, and military applications.
Compared to the 6.5 Creedmoor, it produces more recoil and has a more curved trajectory. However, it has better energy transfer at shorter ranges. Most people consider it more versatile for various applications and big game hunting.
Differences Between 6.5 Creedmoor and .308 Winchester
A shooter must know the differences between 6.5 Creedmoor and .308 Winchester. Let’s take a look at what these differences are.
The 6.5 Creedmoor and .308 Winchester are simply different sizes. The 6.5 Creedmoor has a smaller bullet diameter and shorter case length, which is why you can’t fit .308 ammo in 6.5 Creedmoor rifles, but you can the other way around.
However, even though you can fit 6.5 Creedmoor cartridges in a .308 Winchester rifle, that doesn’t mean you should or that the gun will even fire. It could still cause extraction problems, misfires, and other malfunctions.
The 6.5 Creedmoor typically operates at a higher chamber pressure than the .308 Winchester, partly due to its smaller size. However, if you load the 6.5 Creedmoor into a .308 Winchester chamber, the chamber will be too large to produce the same amount of pressure. This difference will affect the performance and behavior of the cartridge in the rifle.
The 6.5 Creedmoor and .308 Winchester have different performance characteristics, such as trajectory, energy transfer, and wind resistance. For example, when I inevitably tried to shoot 6.5 Creedmoor out of my dad’s .308 Winchester, it worked, just not well. They hit the target sideways like I was shooting an untrue bow and arrow.
The 6.5 Creedmoor and .308 Winchester cartridges are not interchangeable due to differences in dimensions, chamber pressures, and performance characteristics. Attempting to shoot a 6.5 Creedmoor in a .308 rifle can cause malfunctions, firearm damage, or injury.
Invest in a rifle with an interchangeable barrel system to safely use both cartridges or buy separate rifles chambered for each caliber.
For more, don’t miss Can You Shoot 7.62 Out of a 308? (And Should You).
Christian grew up in the Ozarks where he spent much of his childhood on his grandparents’ homestead learning about guns, hunting, and the great outdoors.
An avid traditional bowhunter, much of his writing covers this and other similar topics, but he also covers just about everything from history and economics to motorcycles.
See more of his work at ChristianMonson.com.