[Equalizer_2]

Curiosity got the better of me as the .243 is highly thought of as a multipurpose cartridge but it has always had a much better velocity rating than the 6.8 but I was more interested in the results with comparable barrel lengths.
Interesting results below:
243 Winchester- Effect of barrel length on velocity

It appears the 6mm Creedmore does better in a shortened barrel.
6 Creedmoor barrel length versus muzzle velocity (31 to 17 inches)

 

[122andy]

Usually when comparing cartridges, the one with a larger case volume and smaller bullet wins. This is kind of apples to oranges. Both of those cartridges would have to be built on the AR10 platform. I dont think a 6.8 can outperform anything in that size.

 

[leatherneck]

For people that don't have a lot of knowledge and understanding about ballistics, I've often used the .243 as a very rudimentary comparison of the 6.8 performance out to 100 yards, which is most people's normal shooting distance. I explain that the 6.8 delivers similar energy with a similar bullet weight (frequently slightly heavier) than the .243 for the first 100 yards and does so with less recoil and muzzle blast due to it's smaller cartridge and then highlight it's benefits for young/small shooters.

Since the .243 is generally revered, I often receive nods of approval and continued interest. I leave out the barrel length details as that usually begins to cloud the discussion.

 

[Guts]

Very interesting, thanks for posting. If the 20”-16” barrel numbers were listed as from the 6.8 no one would think twice. A lot less powder and recoil for a better result.

Is the 6.8 SPC chipping away at the pedestal of the mighty .243?

 

[wawaldo2]

All I can say is I own a BHW 24" gun. Running the 90 gr gold dots I can keep up with the 243 100 gr. Not bad for a puny little 6.8

 

[chewbacca]

To Fudds I just say: it’s a mini 270 to fit in an AR…

I always get some kind of response like: 270 is great deer round!
From which, depending on the level of Fudd and my desire or lack thereof to engage more, I will mostly just smile and nod.

 

[Bull000]

I'd be more interested in the .243 vs the 6.8x51?