I have several.
1 stainless Douglas XX prefit for T3 300wsm. Never installed
New take-off blued: .243, 25-06, .270 and I think a 300 Win.
1 low mileage stainless 270 win off a Sako A7, but same threads. also threaded muzzle but not sure of the pitch.
several others in 270, 30-06, 243