You can come up with loads that will suffice for a gong match, and not be able to hold paper in a target rifle match. The big advantage of testing on steel here at home, I can set up my caldwell camera and keep track of every bullet strike, Stop if I need to and go up and look at the target to see that all the bullets are striking point first and not leaving sideway imprints. Repaint and start all over again. Hard thing to do at a gong match

I look for loads that will hold about 2 minutes vertical , the horizontal not so particular as the problems there can come from wind gust and shooter error. But the vertical needs to be as little as possible.
A wise man can always be found alone. A weak man can always be found in a crowd.