Thread: 6mm Creedmoor goats and deer

Originally Posted by Russian 22.

Why does the creed meme have better velocity than the 243? The 243 usually has more case capacity

Its "retained" velocity. While the .243 can match the muzzle velocity of the 6mm creedmoor when loaded equally, the off the shelf .243 win is limited to 95-100gr bullets because it is normally barreled with a 1-9 3/4" or 1-10" twist.
The 6mm Creedmoor runs a 1-7" or 1-8" so can shoot the heaviest 6mm bullets out there which have higher BCs and retain their velocity further out as @Flyblown pointed out.
In addition to that the .243 win case has a max of 60000psi were as the 6mm Creed can be loaded to 75000psi if using small rifle primed brass. It is a highly efficent kick ass little cartridge that is probably closer in comparison to a hot rodded 243win Ackley improved fitted with a faster twist long barrel and loaded hot.
It also has the convenience of factory loaded ammo with those heavy high bc bullets if you are that way inclined.
More case capacity doesnt always equal more speed down range, it normaly means you have to run a slower burning powder and a longer barrel to get the same speed as a highly efficient smaller case shooting faster powder and higher pressure in a shorter barrel.