No I have had zero problems with this saiga from the very get go, with the glaring exception of Winchester bulk ammo from wal mart. When I have shot that particular ammo it runs roughly 3 out of every 5 rounds. This is genuinely a problem with the ammo. This ammo has been a problem in other guns as well. The federal bulk has run 100% as well as every variety of high brass load I have put through it. Many people report problems with the winchester ammo and it is simply best avoided.
Some people do have trouble running lighter target loads in saigas. The first thing to check for is to see if the gun has the right number of gas ports. Some guns were imported with only two ports. They will not run light loads. If you have one it will be warranteed. If the right number of ports are there, the next thing to do is check to make sure they are really open all the way.
If the gas system looks good but it is not reliable with light loads there are a few things that will generally take care of the problem. 1 "break it in" with heavy loads first. 2 alternately is to simply polish the bolt, bolt carrier, hammer, and rails, similar to what I have done here. 3 Another good option is the gunfixer gas plug. It gives a wider array of gas settings to dial in the right amount of gas. It is also a good cure for an over gassed gun.
At the time I wrote that I had a gunfixer plug and the polishing in mind. Despite no reliability problems I polished simply to have a smoother action. I will also likely add a gunfixer plug. The reason in my case is not really reliability issues but rather, I would like to be able to switch gas settings by hand and the gunfixer plug allows this. The factory plug requires some sort of "tool" like a quarter or cartridge rim. The hand adjustment alone makes the plug worth it to me. The wider spectrum of gas settings to choose from cannot hurt either.
There is talk of a self regulating plug being developed. That if it were reliable would be ideal. Right now the current gunfixer plug is a good investment for a S12 owner. I have not gotten it yet because my gun runs fine, but I will. For now I still want to concentrate on the ergos. There is definately more room for improvement there.
I wont address them with the stuff I am currently waiting for but it will probably be the next step. It will be mods that I think really help take the S12 to the next level and make it a much better fighting (or competition for that matter) gun.
I'm glad some people have enjoyed this thread or found it interesting. What I really wont to do is go shoot some 3-gun esque courses on the clock with this gun, a stock s12 and some other shotguns maybe a pump and a coach gun. I wanted to do so at each step of the project to get numbers and quantify the improvements to some extent. Sadly I simply have not had time to do that. I likely will not until December at the soonest. I will in time do so. I personally am very interested to see what the results would be and to do it with various shooters and see what the data shows. One day.