My gun loves the 180gr Win SBTs and I was wondering if anyone knew what powder, primer(win?, case(win?) and COAL tey use. I looked on Winchester website, but found no specs.

Normally the powders used in factory ammo are not available to handloaders. That said, Win claims that their Supreme factory ammo is loaded with Supreme 780. Give that a try.

Go to the Hodgdon Load Center and look up the loadings using W780 powder. You can pull the bullet on a factory round and see if the charge is consistent.