I don't have a STW but I have a 284 Win with a 1-9" twist 29.5" barrel and shoot the 180 Bergers at 2870 fps, they stabilize fine out to 1000yds, I shot a 6.1875" 5 shot group with it today in windy conditions.
I think they will shoot just fine out of your STW.
Regards,
Wayne aka WAMBO