I purchased a gas piston for my AK kit, and it is not marked USA anywhere on the piston.
The place I purchased it from said it doesn't  have to be marked USA on it , because the only
people that make stainless steal gas pistons are American Companies.  Is this a fact , does
anybody have any info on this? and is it true that it is complient if it is not so marked?

                                                                           Thanks
                                                                               Headgear

all the foreign ones are chromed with the possible exception of the yugo.  does it also have a different groove pattern on the sides of the piston head?

If its stainless then it is VERY likely that it is US made. The parts do not have to be marked but many prefer that they are.