Barrel came loose while hunting?

Was in south Texas this past weekend hunting turkey and pigs. Had been shooting turkeys with my (can't be a hunting gun) AR-15 and shooting pigs with my Savage 7 MM STW, when I decided my Savage .257 Weatherby was getting jealous. As I climbed into a stand for the Saturday evening hunt, the Weatherby just felt wrong. At first, I thought it was the front action screw, then as I grabbed the barrel it rotated in my hand :0. To say the least, it was a little disturbing that the barrel came loose and I doubt it would have ended in a catastrophic event had I fired it but, it would not have been accurate. It is an older blued 110 receiver with new SS barrel, nut and lug.

This is an after market barrel I installed about 1 1/2 years ago and have shot and killed lots of things since then. I truly can not imagine how it could of just came loose like that? If any one has a wild ass guess, I'll listen to all possibilities, including owner errors.

I just don't want to repeat any error I did at first (if any), when I re-st the head space this weekend.

Off the top of my head i would say check the barrel nut real close to see if maybe it has a crack in it. Other than that maybe you just didn't get it clawhammer tight to start with.

How did you head space it? Did you use a gage and leave it in while tightening the barrel.If you use a cartridge case as your gage you might miss the feel of tight,I did once.Are you sure there wasnt something between the nut and lug giving a false feel when tightening.I would take it apart and see how the barrel threads feel while turning it in with no lug or nut,just to see if you have a tight spot in the threads,if you dont stone all mating surfaces lightly and clean it with brakleen(crc brand) done outside and blow it off clean and reassemble with a small amount of never sieze and set your headspace and tighten the nut snugly and then hit your nut wrench with a deadblow hammer a couple times and you should be goood to go.

I always put a little bit of nail polish on my threads when installing a new barrel and witness marks on the barrel and nut on the side just above the wood on the stock. Haven't had one budge yet and they are still easy to remove.

The operator. I can say this as I have observed many mistakes by others.

Cartridge as a gauge. I worked the head spacing numerous times to get where I felt comfortable, then set the nut and finished it off with a single tap with a dead blow hammer and rechecked the head space.

I plan on taking it all apart and cleaning all parts. I will check the full length of the barrel thread to make sure the nut spins freely. I just felt that it was weird, that after shooting this gun for a year, that the barrel nut backed off and thus allowing the barrel to spin. It must be a political conspiracy?

As said above, looke for a cracked nut, it does happen once in a while.