We have a vendor that I recently saw was selling S-12 HG's for $20.00 or so.
I'm not sure who, but it was one of our vendors who sell both accessories & converted guns.
Can't for the life of me remember who though.
R&R I think.
http://forum.saiga-12.com/index.php?showtopic=61401
There are detents on the back side of the plug, 1 for each setting so that when you turn the plug there is a small bit of resistance until the pin hits the next setting then clicks into that detent.
If you're talking about the bolt hold open spring, you can go to the carolina shooters supply section and watch the videos Greg has posted. That will show you the proper install of the spring.
I got mine with a friend who I think got them at sportsmans warehouse.
edit, sportsmans guide. Here ya go,,,, http://www.sportsmansguide.com/net/cb/cb.aspx?a=406459
That is wierd , take out the MD and compare it to this pic.
https://www.mdarms.com/index.php?main_page=popup_image&pID=16&zenid=n3gst3rs1pjkrpdgojs3svjko2
Might start reading up on polishing the bolt, it's simple, I did it and did not do any profiling or removing of any material and it improved my cycling about 90 % also are you holding the gun tight to your shoulder?
So you have the MD set on (+) or (5) with wallyworld target loads and what happens exactly? FTE?
Have you looked at your ports? Checked to see if they are all clear and the right size?