Sounds like you might be considedering different weights of bullets in each brand and concluding that the brands with different names will determine the accuracy.
The bullet weight, shape (how much of the bullet touches the barrel) and the velocity determines what the accuracy of your particular barrel will be.
I started my new .30-06 with 150 grain bullets from different manufacturers and was not overwhelmed with the accuracy with any of them. They were all over 1 inch at 100 yards.
I then moved on to 165-168 grain bullets and while they were a bit better, they still weren't what I had expected - they were about 0.8 inches at 100 yards.
When I got to 175 grain bullets, I found my rifle's preference and, even though only a couple of manufacturer offerings yielded good accuracy, I knew I was on to something.
After trying different hand loads, I have one or two 175 grain loads shooting under 0.7 inches at 100 yards on average with best groups just under 0.4 inches.
You will have to look at velocity as well as weight in order to make any conclusions about what your rifle likes as you try different ammos.
Otherwise you'll just have to stumble onto something that works and it might take quite a bit of cash to find the right ammo.