Well I have good news for everybody except the one guy who wanted to avoid making the relief cut in his receiver stub.
This was the first time I've attempted to remove a stub without making the cut. On the FALs I've demilled previously, I took the advise of the FAL gurus over at the files and made the cut before even attempting it.
After hearing the horror stories about 3 foot cheater bars and broken vises, I figured I would take advantage of their experience.
But I wanted to give HB's tools the toughest test I could. So I clamped it all in the vise and began tugging. I have a high quality (read heavy) 6 inch vise on a 8' bench constructed out of 4x4s with a 2" thick work surface (read heavy) I have never had the bench even move before tonight. I waltzed that bench all around the shop and hung my 245lb frame off the breaker bar, but the barrel never budged. The barrel wrench finally failed.
The good news is two fold, first, I exerted way more force than would ever be required to time the barrel on an Assembly or do a relief cut demill before it failed. second even with all that force and ultimate tool failure, the flats on the barrel were still mint.
Lastly, it wasn't the tool or design that failed it was the steel itself. If someone really had to do an uncut demill, the tool will need to be hardened.
Now the pics
1) good solid lock up on the receiver
2) damage to wrench
3) barrel flats after failure.