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