how can I tell if I have a pre baned milled receiver gun thanks new to the ak's
its a polytech legend underfolder
How about posting a picture of it, and maybe a little more information.
The fact it's a Polytech Legend rifle seals the deal. Quite "pre-ban."
But a photo would definately help as it's always possible someone "recreated" a Polytech Legend underfolder and would try to pass it off as the real thing to those not familiar.
This is a Polytech Legend underfolder - if the one you're looking at has the same markings (and might have blonde wood furniture instead of the brown), you're good-to-go: