Here is some helpful information to review to make an informed decision about your manual of arms and to improve your firearm capabilities.
300 Blackout vs 5.56 NATO
https://www.firearmsnews.com/editorial/556-vs-300blk-ammo/483198
300 blackout best barrel length
https://www.ballisticadvantage.com/blog/whats-the-best-barrel-length-for-300-blackout/
What optic height to go with
https://help.trex-arms.com/hc/en-us/articles/360055726234-What-Optic-Height-Should-I-Go-With-
Understanding barrel twist rate
https://www.ballisticadvantage.com/blog/ar-15-barrel-twist-rate-explained/