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FWIW, there are very few commercially reloaded products I'll buy. Black Hills is one of them. Their blue box ammo is all remanufactured. It isn't cheap cheap, but it is cheaper than their red box products. On the Tula ammo you were using, does it have varnished cases? I've seen a number of AR15s disabled this way shooting that kind of Rooskie-import ammo with varnished cases. As the chamber heats up, the varnish on the cases eventually sticks to the chamber. As it builds up, it causes difficulty extracting, eventually building up to the point at which it won't extract. That's when the case heads tear off, leaving the case in the chamber and often a bullet stuck in the bore.

You said you had already fired 30 rounds when the catastrophic failure occurred. 30 rounds of .308 will generate quite a bit of heat, and add to that the heat of the weather so the barrel/chamber wasn't really getting a chance to cool off, and you've certainly got the potential for a failure like that. The bullet may be stuck in the bore simply because enough of the charge blew out down the magwell that there wasn't enough pressure to drive the bullet out the muzzle.

I would certainly have the headspace checked as a precaution, as others have suggested, but if your ammo is varnished, I'd lay the blame there as the most likely cause. If it isn't varnished, then yeah, the headspacing is probably off.