I've got the kit, I've got the US made parts to make it legal, the receiver is ordered. I put the receiver stub in the vise, tried to put my brand new Craftsman 27mm combination wrench on the barrel. It doesn't fit. I filed the flats on the barrel so the wrench would fit. Pulled mightily on the wrench. No movement. Are there magic words? I've used all the Anglo-Saxon ones I can think of, to no avail. Is there a trick or is it just stubborn?