blaserman, the factory barrel was (I think) 9.5"twist. I went to the remington website to get that, but the 7mmSTW is no longer made so they don't show it. Itried both Remington and Federal bullets in the factory barrel. Neither grouped well.

The Hart barrel, I don't know the twist. Have emailed Hart with the question. Will let you know. The Hart barrel is 26". I had the gunshop to work up a load for the gun. It's 140 gr. Nosler Ballistic Tip bullets.