So, you’re in the market for a good all-around cartridge but just can’t decide between the 243 Winchester and the 6.5 Creedmoor? Although they offer similar capabilities in some respects, they offer very different capabilities in others. In this article, we will be going over the similarities and differences of the 243 Winchester and the 6.5 Creedmoor to help make your decision a little easier.
It’s no secret that the 243 Winchester and the 6.5 Creedmoor do not share a common bore size. As the name suggests, the 243 Winchester utilizes bullets that are 0.243 inches in diameter, or a metric value of 6 mm. As its metric naming suggests, the 6.5 Creedmoor utilizes bullets that are 6.5mm in diameter, or a standard value of 0.264 inches.
A diameter increase of 21 thousandths gives the 6.5mm/264 bore size a distinct advantage when it comes to heavy bullet weights. The most common bullet weights for the 6.5mm/264 bore range from 90 grains up to 160 grains. With most factory rifles using a 1-8 twist rate, the 6.5 Creedmoor can take advantage of this whole range of bullet weights, though factory-loaded ammunition generally only goes up to 156 grains.
With its smaller diameter, the 243/6mm bore size does not offer nearly as heavy bullet options as the 6.5mm/264 bore size. The most common bullet weights for the 243/6mm bore size range from 55 grains up to 115 grains. Due to most factory rifles using a somewhat slow (for the caliber) 1-10 twist rate, factory-loaded 243 Winchester ammo does not typically go above 100 grains.
So, the 243 Winchester may be firing a lighter bullet with a smaller diameter, but you may notice that its case is slightly larger than the 6.5 Creedmoor. With a nominal length of 2.045 inches, a 243 Winchester case stands over a full hundred thousandths taller than the 6.5 Creedmoor’s nominal case length of 1.920 inches. This extra case length is one of the main contributing factors leading to the 243 Winchester’s slightly larger case capacity.
One of the primary reasons the 6.5 Creedmoor was designed with a shorter case length was to maximize room for the long and aerodynamic bullets usually associated with the cartridge. A shorter case allows these long bullets to have an ideal seating depth while remaining within the length restrictions of many magazines. In many instances, the same cannot be said when loading long and aerodynamic bullets into the longer 243 Winchester Case.
Perhaps the only real similarity in terms of dimensions shared between these cartridges is their rim diameter. The 243 Winchester and the 6.5 Creedmoor both use the same 0.473-inch, standard short action rim diameter/bolt face. Both cartridges are most often found with a large rifle primer pocket, though small rifle primer pockets are common for the 6.5 Creedmoor as well.
If you’re stuck between the 243 Winchester and the 6.5 Creedmoor, power is probably not one of your top priorities. Though these cartridges may not be powerhouses in the short action world, it is important to know the power limitations of each if you wish to hunt medium to large game.
While the 243 Winchester does have a slightly larger case capacity than the 6.5 Creedmoor, it does not have as high of a pressure rating. According to SAAMI, the 243 Winchester has a maximum pressure rating of 60,000 psi, whereas the 6.5 Creedmoor has a maximum pressure rating of 62,000 psi.
This 2,000-psi increase in pressure plays a large role in the 6.5 Creedmoor’s edge in power. If we look at the Hornady Whitetail 129-grain 6.5 Creedmoor load offering, we see that it produces 2,277 ft/lbs. at a muzzle velocity of 2,820 feet per second. For comparison, the Hornady Whitetail 100-grain 243 Winchester load offering only produces 1,945 ft/lbs. at a muzzle velocity of 2,960 feet per second.
Although the 6.5 Creedmoor may be losing to the 243 Winchester in terms of velocity, it is generating over 17 percent more kinetic energy at the muzzle (in this comparison). This extra energy, paired with a larger bullet diameter, heavier bullet weight, and often higher sectional density, makes the 6.5 Creedmoor an arguably better choice for hunting medium to large game.
Although the 243 might not be quite as powerful as the 6.5 Creedmoor or as well suited for large game, it is arguably a much better cartridge when it comes to varmint hunting. Perhaps the biggest key to the 243 Winchester’s success as a varmint cartridge is its range of bullet weights.
Unlike 6.5mm/264 bullets, which typically only go down to 90 grains, 6mm/243 bullet weights range all the way down to 55 grains. A bullet this light, paired with the large capacity of the 243 Winchester, can produce the extraordinary velocities usually associated with varmint hunting. In fact, Winchester’s Ballistic Silvertip 55-grain 243 Winchester offering has a blistering muzzle velocity of 3,910 feet per second.
That is not to say that the 6.5 Creedmoor cannot be an effective varmint cartridge. However, it does not compete with the 243 Winchester’s velocity range. Perhaps the most comparable factory load for the 6.5 Creedmoor is Nosler’s 90-grain Varmeggedon offering, which has a muzzle velocity of 3,300 feet per second.
While this figure is not slow by any stretch of the imagination, the 243 Winchester load referenced is producing about 18.5 percent more velocity. This extra velocity not only gets to the target quicker but also equates to much flatter trajectories (especially at short and mid ranges). Less drop is important in varmint hunting scenarios, where distances may be unknown and quick shots are often required.
With proper setups, the 243 Winchester and the 6.5 Creedmoor are very capable long-range cartridges. It must be noted, however, that the 6.5 Creedmoor was designed with long-range in mind, whereas the 243 Winchester was designed as a hunting cartridge. This can present challenges for long-range potential--at least with many of the factory rifles and ammunition offerings on the market.
As mentioned above, many factory-chambered 243 Winchester rifles utilize a 1-10 twist rate barrel. While this may be optimal for stabilizing the wide range of bullets the cartridge was designed for, it is not fast enough to stabilize many of the heavy and aerodynamic 243/6mm bullets ideal for long-range shots.
Because of this twist rate as well as magazine length limitations, factory ammunition offerings seldom go above 100 grains (usually a hunting-style bullet). That is not to say that the 243 Winchester is not capable of similar ranges to the 6.5 Creedmoor. However, custom rifles (with fast twist rates) and custom loads (or reloads) are a necessity if you wish to push the cartridge out to these ranges.
Unlike the slow twist rates found in most factory 243 rifles, nearly all factory-chambered 6.5 Creedmoor rifles utilize barrels with a 1-8 twist rate. This twist rate is fast enough to stabilize even the heaviest 6.5mm/264 bullets (in most cases), which are ideal for long-range.
Compared to the 243 Winchester, the 6.5 Creedmoor has substantially more factory load offerings that utilize aerodynamic bullets ideal for long-range shots. So, if you wish to shoot long-range and intend to stick with factory rifles and ammunition, the 6.5 Creedmoor is a much better option in almost every case.
For many, especially new shooters or those needing fast follow-up shots, recoil is a make-or-break factor. Although the 6.5 Creedmoor and the 243 Winchester do not produce much recoil compared to many other centerfire rifle cartridges, there is a noticeable difference between the two.
Because the 243 Winchester is generally firing much lighter bullets than the 6.5 Creedmoor, recoil is typically much less out of the same-weight rifle. With a muzzle velocity of 2,960 feet per second, Winchester’s 100-grain power point 243 Winchester load produces around 10.35 ft/lbs. of recoil out of an 8-pound rifle.
With a muzzle velocity of 2,820 feet per second, Winchester’s 129-grain power point 6.5 Creedmoor offering produces around 13.51 ft/lbs. of felt recoil out of an 8-pound rifle. While 13.51 ft/lbs. is not considered excessive recoil by any means, the 6.5 Creedmoor produces just over 30 percent more recoil than the 243 Winchester (with the loads referenced).
Which One Should I Get?
The 243 Winchester and the 6.5 Creedmoor are two of the most popular short-action cartridges currently available. With the vast number of rifle and ammo combinations that exist for each, deciding on one can be a tricky proposition.
If you want as little recoil as possible while still having enough power to take medium to large game when needed, the 243 Winchester is a hard option to beat. With lightweight bullets at blistering speeds, the 243 Winchester makes for an excellent varmint cartridge as well.
The 243 Winchester is a very capable long-range cartridge--if you are willing to go custom. From the factory, you will be hard-pressed to find a rifle and ammo combination capable of the extended-range shots the 243 Winchester could potentially make. If custom is not an option for you, many of the factory-chambered 6.5 Creedmoor rifles and ammunition choices are capable of excellent long-range potential.
Due to heavier bullet weight options with much higher sectional densities, the 6.5 Creedmoor is also much better suited for large game than the 243 Winchester. Although these heavier bullet weight combinations produce more recoil than the 243 Winchester, the 6.5 Creedmoor does not produce excessive recoil by any means.
So, as you can see by the strengths and limitations of each cartridge, making a choice can be very difficult. Regardless of which cartridge you choose, hopefully, this article made your decision a little easier.