That's great. Unfortunately, it's a known fact that the quality control on the Saiga 12 is uneven. Most are just fine. Some can be temperamental (although word has it a break in of 100 slugs or so will wear them in right nice). Some are referred to as "vodka specials."
IMO, the S12 is a gun for the enthusiast; someone who wants something cool, but understands that it may be temperamental and require some fiddling to make it work right. There's other shotguns that are far more likely to work great right from the box.
+1 FN SLP or Benelli M2 or M4 or Mossberg 930. All will go bang for 200,000 rounds or more with routine or even less than routine cleaning and maintainence out of the box. You don't have to "modify" ("fix") the top tier guns.
