Lothar Walther pre-threaded & chambered .300 WM 26" 1-10 twist.
I have one in .308 (24" 1-10) and one in .223 Rem (24" 1-8). Both shoot tight and clean up easy. Plus they usually have an inventory in stock to pull off and ship to you quickly.
I just wish LW would expand their PTC line up a bit... 6 BR in a fast twist, 6.5x47L, large shank for the PTA series...