Took it out for the first time and the flash hider went downrange somewhere during the first magazine.   Threads are pretty badly sheared, it will go back on but is pretty loose.   Measuring what is left comes up short of a min diameter I found elsewhere for 14mmx1 threads.

Bore looks concentric to barrel so not sure what happened.   It was engaged with the front sight pin indexing it in place.  I did notice that a little extra weld was left on the front sight base and if it had been completely removed maybe I would have gotten another thread of engagement.

I thought the threads were factory or did Century somehow goof them up when breaking the weld and removing whatever was on there before?   Hider seems undamaged so not sure what caused it to go airborne.

At this point unsure what to do, if I send it back to Century, its a pain and shipping is expensive and who knows what I will get back.   Should I just have a smith recut the threads to 1/2x28?   I could then mount a SDN-6 although I am a bit wary given I already launched a hider off of it...

Bullets didn't seem to keyhole at 50 yards, but at that point I didn't shoot it much more than a few times at paper.

well, I must be the only one...  going to have it locally threaded 1/2 x 28 and on occasion use a SDN-6.   Hopefully it won't be too tough on it.

Never had an issue with either of mine, threads were perfectly cut and the concentricity was measured spot on. Sounds like yours got smacked around somewhere down the line.

About 100 rounds through mine so far.  Everything stayed put on mine.

I changed the birdcage out on my Mini to a heavy muzzle break and 200 rounds later no problems.

I would be surprised if you could even thread a 7.62 barrel 1/2x28.  Is there enough wall thickness to do so with threads so small?

AAC sells a blackout for .30 with 1/2x28 threads.

Here are people going up to .355-.357 bore with that threading which does surprise me.

http://www.300blktalk.com/forum/viewtopic.php?f=136&t=78535