Someone expressed concerned about frame distortion, and I am a bit concerned,as well, but the plan is to dose the barrel threads with penetrating oil and allow it to stand for 24 hours. I plan to then support the frame as firmly and completely as possible with closely fitting Delrin vise inserts to distribute the torque forces over the entire frame; no point loading. I guess we'll know if that is enough here in a couple of days.
By the way, I received my 11-degree forcing cone reamer yesterday, so all is now in hand and ready to go:
TBR