I don't have any carbon wrapped barrels. I am old school but I do have some custom guns built before the fast twist craze. My current .264 / 6.5 is in need of a new barrel after nearly 40 years. It is a 264 mag on a Sako action. Will definitely be going with a faster twist. Debating what new cartridge will work on this gun. The 264 mag is overbore. Looking for something a little more efficient. 6.5 PRC? Even a 7mm PRC would work. Plenty of magazine space for either.
Well I'm getting partial to the 6.5x55 AI
Factory loaded lapua launches a 120 6.5x55se from that chamber at over 3100ft/sec.
I'm planning on working up the fireformed cases with the 127lrx to 3200 feet/sec.
And a vld 140 to over 3100.
Most American ammo is loaded way below what a modern action and lapua brass can stand.
With a fast twist barrel like 7.5 or 8 and that case I'll get there with a little less than 50 grains of H short cut and a standard primmer.
Things to consider in today's component market.
Only thing I would have done a bit different is allowing a slightly longer free bore.
The way it is I have to setback the bullets on factory loaded ammo to clear the rifling.
Kinda defeats the purpose of an AI
ITS A VERY EFFICIENT CASE over 120 years old.
Seriously worth a look in a strong action and good European brass.