Slowly gathering parts that have multiple applications (front rail, etc), but still kinda stuck on the chamber. I have two main reasons for the gun. 1: sport shooting 2: deer. I've heard both sides of pro/con on using 5.56 for deer, and while I'm sure there are positives for both arguments, I'm not one to want to end up leaving an injured animal to suffer and die as a waste. So, now I need to figure out what chamber to use on my AR platform to feel confident regarding the previous statement not happening. I'm also leaning towards attempting, if possible, to build one lower and have multiple uppers down the road, that way I can swap between a couple/few different calibers at some point. Mainly at this point though, I'm needing the dual use upper to start with. Any help is greatly appreciated!

Oh, almost forgot. No need to reach out and touch someone, live in the appalachians, so 100 yds would most likely be the furthest shot to worry about, and even then thats gonna be rare.