I fucked up my m4e1 and stripped the threads on two of the screws. Specifically the two top right (when your pov is looking down the barrel).

Does anyone know if a gunsmith is able to fix this? Should I just tap it myself (if so, what size should I change it to? Am I better off just buying a new one?

OR

Should I just leave it be? I recently just finished building a new AR with an LMT upper for my shtf setup. I  was planning to turn it into a 300 blk SBR with a SPS300 can just to have for fun. It wouldn't be my go to rifle

I would greatly appreciate your help, thanks!

If it's the M4E1 threaded upper receiver, just buy and install a new barrel nut. If it's the M4E1 Enhanced upper receiver, then you'll probably have to tap it.

Depending how badly stripped you could always tig weld and retap. Might cost more than its worth if you are not capable yourself or have friends that can.

Another option is helicoil or just some non-removeable locktite.

I’m assuming this is the enhanced upper?  If yes, I wouldn’t worry about it, you have 6 more screws holding it on.  Another option would be to chase the threads with the correct tap size. You may not get as much “bite” from the screws after that but at least they will be there.  You could also buy two course threaded screws and try to screw them in to the fine threads.  

They must be using stronger screws now because the heads used to pop off easily with just a little torque/ resistance.