if it was made in a russian factory at any point, it is not banned from further importation by executive order along with all of the other small arms that were banned in that same executive order.
it has not to do with europe.
many ranges will not allow it because most of the military surplus uses a bi-metal jacket on a steel or lead core. they are worried about potentially sparking a fire, increased penetration into their backstops and potentially environmental issues. as such, shooting it in most indoor ranges i've been to is not allowed and many outdoor ranges do not allow it for environmental reasons.
check gunbroker.com if you need to find mulsurp. expect to pay somewhere around $350/1080 tin before shipping for 7N6 milsurp, which although is very reliable and accurate (for an AK) is also corrosive. new production ammo will vary in price, but expect it will run you around the same.
these prices are only likely to go up from here on out, as getting more is now impossible.