I shoot the 22-243 Winchester. Mine shoots 48gr Rel25, Fed210, 75gr Amax at 2.750. I don't know what velocity it's getting as I haven't chronoed it. I have a new 22-243 that I will be trying Retumbo in.
One built off Remington 700 SA 6mm and one off Rem. SA 22-250. One has a 1:8 Shilen Select match, one has a Kreiger 1:8. I have not shot the Kreiger yet and I just sold the Shilen. Brass forming is simple. Put a 243 case through the sizer and thats it. No fire forming.