First, for factory ammo I think you are doing great. MOA with the stuff you have tried is probably as good as you will get.

If you want better factory groups go to the match ammo. Federal Gold Medal is my go to stuff if I need to shoot factory. Hornady has some that seem to be good as well, but, I have not tried it.

Bullets for reloading. My .223 is really picky about bullets. Some people claim they can shoot bugholes with any .223 round out there. I can't. Even reloading, if I load std bullets in it, I get 2MOA groups. It doesn't like Hornady match bullets but it loves Sierra Matchkings. It looks like the Norma's will work too. I also dropped group sizes when I switched from H335 to Varget powder.

So, with a little load development or better factory ammo you can probably get to your goal.

As to 'listening' to others on the internet, take it with a grain of salt. I've seen people clain .5 MOA when most of their groups are the size of their fist. They just pick the best three rounds they had that day.

The 6.5CM has garnered enough attention that every Tom, Dick and Harry is shooting it and they have to claim better than .5MOA or no one will congratulate them. It is NOT going to shoot better groups just because it is a 6.5CM.

And, each rifle will like a slightly different combination.

So, first get some good factory match ammo, and then get some good bullets to reload. My .308 seems to like the Hornady ELD-X match bullets.