If you have the balls you can try it yourself. Thats the route I'm going to go. Yes you can completely mess up a barrel this way but if done slowly and correctly then from I've seen its not difficult. About 30 min of research and I would feel comfortable doing so. Hacksaw, round hose clamps, sand paper, file, brass screws, abrasive compound, and the 1/2x28TPI die and you are set.
From what I've seen people do is use the hose clamps to prevent the hacksaw from moving while cutting the barrel. Then use the file and sandpaper to make the cut square and flush. Then use the abrasive compound with a brass screw chucked into a drill and then crown your barrel. That is also another easy thing to do. Then all thats left to do is use the die and thread the barrel. Everything I read say if you make the end of your barrel square with the file and sandpaper then your threads will also be square if done correctly.
Like I said, I have yet to do this but I plan on doing it fairly soon. Do it at your own risk. You'll pay someone 100 bucks to do it or you can do it yourself for 20. But if you mess up then you'll need a new barrel which is 150+ dollars.
If you're threading the end for a suppressor, please do not use a die. Hate to see anyone ruin a new suppressor because their threads are off just a hair.
No worries on this end. I don't plan on using a suppressor on this rifle ever. I'm pinning a compensator that specically can't accept any suppressor mounts for this reason.
I charge $80...cut, crown and thread. For $100, I'll put on a thread protector.