When shooting service rifle,
Remember safety and function should come before accuracy.
The National Match m14/m1a with good ammo should shoot the xring out to 600 yards all day. Most people will lose more matches to malfunctions then to inaccurate ammunition. When I competed I used small base RCBS dies for function and Winchester large rifle primers, 168 hpbt with h4895.
With this load I could clean a 600 yard target, if you shoot 1000 yards switch to the 175 hpbt, 168s drop subsonic out to 1000.
Try it, shoot Service Rifle, shoot local matches go to Camp Perry, it's good fun and the people are great!
Distinguished rifleman
NRA master