Good day folks!
I am brand new to the AR world. This disclaimer is here so if this thread comes off as naive, or I come off as naive, it is because I am naive. With that said, here goes my first thread ever about a brand new rifle....
I am getting my new Colt 6720 off of layaway in a few weeks. I purchased the Colt due to outstanding reviews and I have never owned a Colt before so I figured it was as good of time as anything to. I have had years of .223 experience but they have all been bolt action rifles. While most of this stock rifle will suit my needs while I break myself in on the AR, I would like to upgrade the rail system to something that can grow with me. Now for the questions, what are the constraints that I will need to know when looking for a rail system (length, weight, compatibility, etc...)? Also, I have been told I will need to upgrade the gas system (naive moment). How much work does this entail? Is adding a new rail system to the Colt something a novice in this type of rifle can do? Is a gunsmith required or it is as simple as exchanging parts?
Along with responses to this post, please let me know if I in any way did not follow proper thread etiquette. Since I am new all the way around I want to make sure to do things properly so I can gain as much knowledge as possible. Thank you all so much for all of your input ahead of time and I look forward to checking in and reading any/all replies.

