Normally I'd say go for it. But the availability of parts are just about non-existent. I have a friend that's been looking for a bolt carrier for months and hasn't been able to find one. If you do decide to build one and find parts you can get around having to buy tools to build one if you buy a barreled upper. It's jut a matter of putting it together.
USAF Retired, CATM, SC CWP, NH NR CWP, NRA Benefactor
To preserve liberty, it is essential that the whole body of people always possess arms, and be taught alike, especially when young, how to use them... -- Richard Henry Lee, 1787