I know this has been hashed and re hashed over and over on the interwebs over the years but . I have A " Made in china " SKS from factory 906 type 56 SKS It doesn't say norinco on it though. I hear the " made in china " type 56 was a military surplus imported to the US and the norinco's were the commercial production model sks . Is this true? And if it's not true what is the difference?