I have one in 223 very well built and accurate,had no problems with it.Now my saiga 12 different story
Well I bought one brand new and ran a box or so of high brass thru it no problems.Then I converted it with parts from css well about 300 rounds of walmart bulk pack I noticed my carrier was cracking where the op rod screws in,(sad day)I welded it up hasn't cracked anymore but makes you wonder if its made out of melted down tractor parts:confused.
Hmmm. What port size and how many?
I went with 4 ports at .073 diameter. No problems.
Have you tried putting tape on the (inside) face of the rear trunnion, to see if the carrier slamming into it?
One of the vendors over on S12 is making carriers now, but not sure who it is? In case you end up needing one.
Its a 3 port gun I think I drilled them to .092,And yeah I thought maby it was getting over gassed but I have a adjustable gas plug on it and I run with it on a low setting to where it hardly cycles and all the paint is still on my trunnion so I don't think that was the case,Over at the saiga forum another guy had the same problem they claim the carrier wasn't heat treated right or it was soft metal.
Look at the gas block pic in post #7.
No one has this, it's something I came up with
I see the hole your talking about but the saiga has a bleed hole from the factory