They are not importable for several reasons...
- they would fall under the NFA... all NFA weapons were banned from import except for LE / Govt sales... this was part of the GCA of 1968... this is why one never sees FACTORY imported SBR's, SBS"S and SUPRESSORS.
- there is a trade aggreement between us the Russia that specifies in great detail the firearms that cen be imported for commercial sale. Here is more info...
http://www.cs.cmu.edu/afs/cs.cmu.edu...et_imports.txt