Long time no ping! Hello again to all.
Always satisfying work on old guns. If you want some idea of what projectile weights will generally do best, check the barrel twist. Faster twist stabilise heavier projectiles... Never had a .243 so can't comment what specific weights, but driving a lighter projectile faster will tend to shrink groups.
One comment though. (It's not just you, the world seems to have gone mad on this) Is on videos... please please turn your phone sideways!!