This article was written by Travis Fox
243 Winchester vs the 6mm Creedmoor: Is one better than the other? If you were born less than 20 years ago you may have not heard of the 243 Winchester, and if you are over 50 years old you may not know the 6mm Creedmoor exists. Let’s examine the differences between the two, “by the numbers”.
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Starting with SAAMI
Here’s the SAAMI specs for each of these cartridges:
While these cartridges are pretty similar, there are a few key differences:
The 6mm Creedmoor is more geared towards the heavier longer high-BC bullets that are now popular with long range shooters using 6mm bullets. With a tighter freebore spec, the 6mm Creedmoor may also produce more accurate groups in some circumstances.
Rifles: 243 Winchester versus 6mm Creedmoor
If you are looking to buy an off the shelf factory rifle almost every manufacturer makes a short action bolt rifle in .243 Winchester. Coming in right behind the 30-06 and the .308 the .243 is one of the most popular rifle cartridges used for deer hunting in the U.S. Think about how many people you know with a .243 Winchester then, think about how many animals have likely been taken with that cartridge, lots! Here’s a side by side from Bergara:
While the 6mm Creedmoor is not as prolific in factory rifles, it is available. This is an upcoming star cartridge in my mind. I predict more companies offering this cartridge choice in the future. Discussion below as to why.
Off the shelf ammo availability
That is a clear winner by the .243 Winchester by a long ways! Here’s a side by side showing ammunition offerings for 243 Winchester and 6mm Creedmoor at Midsouth Shooters Supply:
At Midsouth, there’s nearly double the ammunition choices for 243 Winchester compared to 6mm Creedmoor. That says a lot!
Bullet Stability with Factory Barrels
Using the Berger Bullet Stability Calculator, we looked at stability of different 6mm bullets in a 1:10 barrel (typical for 243 Winchester) and 1:7.5 (typical for 6mm Creedmoor). Here’s the summary:
As you can see in the diagram above, a typical 6mm Creedmoor barrel will stabilize a much wider variety of bullets (with a focus on long, heavy high-bc bullets). The 243 1:10 barrel will only stabilize the 95 grain bullet from this example selection.
With reloading, the data shows the 6mm Creedmoor having a slight advantage over the .243 Winchester when it comes to velocity. The slight increase is due to the bullet being seated further out of the neck which allows for an increase of powder volume. For example loading a 100gr bullet, the max charge of H1000 in a 6mm Creedmoor is 49gr vs the .243 Winchester of 47gr. This is per the online reloading manual, Hogdon Reloading.
Comparing factory hunting ammunition from Hornady provides a real-world comparison of how ballistic performance can differ between these two cartridges:
Drop Table: 243 Winchester 90 grain ELD-X Hornady Precision Hunter
Drop Table: 6mm Creedmoor 103 grain ELD-X Hornady Precision Hunter
These differences become more clear when you look at a graph of these results:
Summarizing, 6mm Creedmoor beats 243 Winchester at 1000y with 252.2 greater fps and 54.5” less drop at that distance.
Here’s a quick summary of the comparison of these cartridges:
- More similar than different
- Both are great hunting options
- 243 Winchester has broader range of factory ammunition
- Custom fast twist 243 will compete with 6mm Creedmoor
- 6mm Creedmoor is best choice for PRS and similar
- 6mm Creedmoor chamber geometry is tighter and more geared towards precision
My .243 (1:8 twist rate) and Gavin’s 6mm Creedmoor head to head are very similar rifles to shoot.. Both are custom built guns and weigh very similar. Reloading, I do like the Creedmoor based cartridges to load. They don’t require trimming much so that step is not often needed. That is a minor issue though. Ultimately you have to decide for yourself which is better for your needs!
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