The 6mm bullet diameter is making its name in the hunting and shooting industry. Something about the 6mm just makes it one of the most effective long-range bullets out there. Two of the more common 6mm cartridges are the 6mm ARC and the 6mm Creedmoor.
Here is the short answer:
The 6mm ARC is a better choice for short-range hunting and tactical applications as it is more compatible in the AR-15 platform. The 6mm Creedmoor is better suited for long-range target shooting as it has better ballistics and more energy.
Now that we have looked at the short answer, we can look closer at each cartridge their ballistics, and how they compare in-depth.
In-Depth Look at the 6mm ARC
The 6mm ARC (Advanced Rifle Cartridge) was developed by Hornady to be an improvement to other rifle cartridges chambered in the AR-15 platform. This cartridge uses a 6.5 Grendel necked down to fit a 6mm bullet allowing it to use higher BC bullets so it is more effective at long range.
The 6mm ARC has a short, fat case that is designed to fit into the AR-15 magazine as an intermediate cartridge that still has enough energy to effectively take game like deer and coyotes but not so much recoil that it becomes difficult to shoot. Think of this cartridge as the middle ground between the 5.56 NATO and the 243 Winchester.
Here is a ballistics chart of the 6mm ARC with a 108-grain ELD Match bullet:
| range (YD) | drop (IN) | wind drift (IN) | velocity FPS | energy ft-lb |
| 0 | -1.5 | 0 | 2750 | 1813 |
| 50 | -0.1 | 0.2 | 2665 | 1703 |
| 100 | 0 | 0.6 | 2582 | 1598 |
| 150 | -1.1 | 1.4 | 2500 | 1499 |
| 200 | -3.7 | 2.5 | 2420 | 1404 |
| 250 | -7.7 | 4 | 2341 | 1314 |
| 300 | -13.4 | 5.9 | 2264 | 1229 |
| 350 | -20.7 | 8.2 | 2188 | 1148 |
| 400 | -29.9 | 10.9 | 2113 | 1071 |
| 450 | -40.9 | 14 | 2040 | 998 |
| 500 | -54 | 17.5 | 1969 | 929 |
In-Depth Look at the 6mm Creedmoor
The 6mm Creedmoor is a popular cartridge that was developed by Hornady in 2007. It is based on the 308 Winchester case, but it has been modified to shoot 6mm (243 caliber) bullets. This essentially makes it a copy of the 243 Winchester.
The 6mm Creedmoor is a round that has good ballistics and is very effective for taking game like deer. It has a low recoil making it Ideal for smaller shooters or those who are shooting for long periods of time.
The issue with the 6mm Creedmoor is that it is not a super popular cartridge. And when you compare it to the much more popular 243 Winchester, you will find that the 243 Winchester performs the same as the 6mm Creedmoor.
Here is a ballistics chart of the 6mm Creedmoor with a 107-grain boat-tail hollow point:
| range (YD) | drop (IN) | wind drift (IN) | velocity FPS | energy ft-lb |
| 0 | -1.5 | 0 | 3000 | 2138 |
| 50 | -0.2 | 0.1 | 2912 | 2014 |
| 100 | 0 | 0.5 | 2826 | 1897 |
| 150 | -0.9 | 1.2 | 2741 | 1785 |
| 200 | -2.9 | 2.2 | 2658 | 1679 |
| 250 | -6.1 | 3.5 | 2577 | 1577 |
| 300 | -10.7 | 5.2 | 2497 | 1481 |
| 350 | -16.6 | 7 | 2418 | 1389 |
| 400 | -24 | 9.3 | 2341 | 1302 |
| 450 | -33 | 12 | 2265 | 1219 |
| 500 | -43.8 | 15.1 | 2191 | 1140 |
In-Depth Comparison
The 6mm ARC has a shorter overall length and is designed to fit into the AR-15 platform, making it a great choice for quick transitions from short to long range hunting and tactical applications. The 6mm Creedmoor is better used in bolt action rifles and can be found in some AR-10s.
The 6mm Creedmoor is a cartridge that has been around longer than the 6mm ARC so it is going to be easier to find. However, the 6mm ARC is less expensive per round due to the fact that it uses a smaller case and less powder than the 6mm Creedmoor.
For hunting applications, the 6mm Creedmoor is generally the better round because of its higher energy and better energy retention at long range. This is not to discredit the 6mm ARC in any way as it is still a round very capable at taking deer sized game, it will just not do it as well as the 6mm Creedmoor.
When it comes to recoil, the 6mm ARC is going to have less recoil than the 6mm Creedmoor. This is because the 6mm ARC uses less powder than the 6mm Creedmoor and is going to therefore has less recoil.
Conclusion
In conclusion, the choice between the 6mm ARC and 6mm Creedmoor will largely depend on the intended use and personal preferences of the shooter. The 6mm Creedmoor is a better hunting cartridge that is going to have better long-range performance. The 6mm ARC is going to be a less expensive round better suited for tactical applications and hunting at close range.