Thread: 6 Creedmoor

Originally Posted by Marty Henry

Isn't the main difference the twist rate? Put a fast twist barrel in a 243 and there'd be bugger all difference.
Ok there's a bit of refinement in the case geometry and in the 50s when the 243 was introduced Americans were in love with varminting, so light bullets were the preference and twist rates kind of refected that across a whole range of cartridges. The 22 250 started out at 1:14 for example now with the development of interest over time of chucking heavier bullets you can get one in 1:8. Maybe if the 243 had kept pace the creedmore may never have been more than a market ploy to sell new guns.
Oh look for some reason it's in sterio

The 22, 6mm, 6.5 Creedmoors are superior to the 308 based cartridges for many reasons

Absolutely the old cartridges can still get the job done but things advance, or we will still be only shooting 250 Savage, 6.5 x 55 & 7 x 57 etc & they all replaced some other cartridges, spears etc...

Originally Posted by Kiwi Greg

The 22, 6mm, 6.5 Creedmoors are superior to the 308 based cartridges for many reasons

...

Such as?

Originally Posted by STC

Such as?

Google it

Originally Posted by Kiwi Greg

Google it

"many reasons" why something you are trying to sell is superior, and you cant name a single one? :-)

Tells me everything I need to know, thank you!

Originally Posted by STC

Such as?

I lifted this straight out of the internet:

The 6mm creedmoor case was based on the 6.5 creedmoor case. Which was based on the 30 TC case. The 243 is based on the 308 case.

The advantage of the creedmoor cartridges over their 308 based counterparts is this. Having a shorter case allows you to seat the bullets further out of the case and still fit into a standard magazine. Eliminating some of the space that the long bullets protruding into the case of the 308 based counterparts. Increasing Available space for powder in one way.

The sharper shoulder and straighter contour of the case walls allows increased powder capacity in the shorter case. Also the 6mm creedmoor will have a tighter twist rate to stabilize those heavy for caliber bullets.