I have a couple of these barrels and they are both tapped, by me. If you haven't already looked in the stock for your choke removal tool, I would start there. If you can't find it, you can get additional chokes and removal tools from Magnum Research for a pretty good price, as they are using the TC system just like the NEF barrel you have.
These tubes can get pretty darn tight even with lock tight on the threads, so it doesn't surprise me. with the choke tube removal tool and some leverage, it should come right out.
I took the scopes off of mine when the 45 LC barrel came out, as it is more accurate for me. But, with a good scope, I was getting 3" groups @ 100 yds with mine. Plenty good for hunting.