But why handicap the 243, both use AI mags, rugers throats are usually long and at one time they put the fast twist on their 243's. The 9 twist wont stabalize the Hornady 108eldm. Seems they would sell more with the faster twist to me.
It would also be cheaper and more efficient to make one ROT in their 0.243" bore American Rifle barrels.
Remington did that with the 243 and 6mm when the 6mm was introduced with a 1-9" ROT barrel.