I had the same problem a couple of weeks ago. The wrench I have is the DPMS Muti- Tool and it is out of spec. I called DPMS and talked to an engineer there and he said that they had a bad batch where the pins were wide. I probably also have the same FF tube. All I did was take a file and lightly file a little off the outside of each pin making sure to contour it as I went. Did this until it fit with a little slop. I asked the engineer if it would work ok first before I did it. He said it should work ok.
You decide whether you want to modify or return though. If you take to much and it breaks it's your problem not theirs. I'm sure if you wanted to return it that they would make it good. I did it and installed a barrel and it worked fine. Removing might take more pressure and it may fail but I doubt it because the pins are soft.