223 bullets and 1:7 twist

[gewehr76]

Hi reloading experts.

I'm new to this cartridge 223 rem. I have 2 questions

What is the best bullets to use in ar15 rifle with 1:7 twist ratio? The barrel is 20'. In other words what bullet weight and powder combination works best?

Other question is whether 1:7 twist barrel harder on bullets, being faster than lets say 1:9 or 12.

Any input please.

Thank you

 

[Paulinski]

55gr - 80gr

Although the 80gr would have to be single loaded.