I have two Nucleus actions with barrel nut Barlocs. Current plan is to take them and a deadblow hammer to the range this weekend. I'll satisfy my own curiousity if nothing else.
Current planned protocol is shoot a group, smack barrel, shoot a group, smack barrel harder, shoot a group, etc.
For both, I am gonna start them cold in the AM and heat the barloc up with a little torch just to check temp difference as well at the end of a series.
If I don't get any POI movement, I will make index marks, pull the barrels, re-install them, and give it another go to see if installation makes a difference.
I don't care about return to zero on a barrel change, yes, I think the Barloc is gonna give the most variability of the systems out there. Most of the discussion was here was general stuff and philosophy of use. I get all that.
If anyone has any specific information, experience, comments about the POI shift on an installed Barloc, well, I'd like to have it before my test. It is interesting to read the comment about the two barrels and three results of different barrel headspacing systems. Not sure how much causation is in the correlation, but something to explore.
As for personal experience, once in more than 500 rounds have I experienced anything I would consider a POI shift. But, I was also switching from virgin brass to my second firing, so I chalked it up to that. It is my match gun, gets drug around everywhere I shoot, goes in soft cases, sometimes with a second rifle, has a suppressor on it most of the time, and doesn't get babied. I followed ARC's procedure to the "t" in installation, and torqued using a Borka.