Huh? What? Who said anything about clamping a receiver in a vice?
Even with using insets around the barrel, some of those stubborn barrels will still want to turn in the inserts. I don't change barrels often enough to buy a proper barrel vise. Using the insets in an ordinary machinist vise, you can still wedge a small metal block between one of the barrel grooves and the vise jaw. NOTHING wrong with that. It stops the barrel from wanting to start turning in the inserts.
The first time I tried this was up at one of Hungry's clinics and we were turning the barrel in the inserts even after using the pipe on the vise handle to tighten it down. We were trying to get the barrel off.
Obviously you have gotten the completely wrong idea about my post.
No, I understand exactly what you are describing. Improvised tools can be a poor substitute for proper ones. Sometimes the job gets done, sometimes there is damage. A conventional vise does not do a very good job of holding a barrel even with blocks. Using a pipe on the vise handle is poor practice, and frequently results in damage to the vice, and doesn't necessarily get the job done. All very well if you are working on your own guns. Really bad idea if you are working on someone else's.