You're pretty new to this platform as you said, I'd buy more ammo and get to the range and practice with the gun before you start swapping stuff out on it. We've seen lots of people here rush out and buy stuff only later to find out it won't fit their rifle.

My suggestion. Get familiar with your rifle. Read up on the AR functionality and understand how the rifle works and how different accesories will fit on it. That will help you a ton and probably will save you lots of time and money.

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Still carrying my S&W 642