DO NOT Allow the lack of tools or equipment keep you from building one if that is what you want.
we have too many Gunsmiths and shops here to keep you from that.

benefits of building.

I want this lower with this upper and a hard-chrome BCG with all Magpul furniture and a Number # charging handle. Buy once, build it.


Benefits of a pre-built

Buy, Shoot

Granted with a prebuilt you are shooting what someone else put together, So if you change ANYTHING you are essentially buying that part twice.
even if its Furniture. you bought the cheap furniture, now you are buying the Nice stuff.

Honestly there are pros and cons on both sides that only you can decide about.