I'll be honest. I built mine on the premise that some of the factory 308 guns were basically a converted 7.62x39 build, after all those comparison photos that were shared of the Saiga .308, the Yugo, and I think a Galil? bolt. The locking lugs are the same on some of them, and so was the size of the lugs on the trunion.
My SVU clone is a rough ride with surplus military ammo (which we all know is really hot) for one simple reason - the gas port is too large. I cut it to the standard AK-47 size of gas port. .177" I believe. Venting the gas tube was an IMMENSE help!
The load I use in it now is one of the recommended accuracy loads on the Nosler website. You can shoot it all day long and it feels like a normal AK-47.
I inspect it regularly since it is a bullpup and I don't want it blowing apart and into my face. It is built on one of those DPH bent flats (remember those?) and is mostly a Romy G kit. I've had about 150 rounds through it, both hot and mild, and no signs of excessive wear or peening. Headspace has not budged at all. And I check it after almost every range trip.
The problem I had with the gas block was due to it being bored out too much, making the base too thin, and the replacement block I installed is A-OK.
I would have no problems using this as a "go-to" gun.
If I were to do it again, I would:
1. Use some 4130 tube steel as the base, with a factory gas block welded to the tubing.
2. Drill a smaller gas port.