It's Hungarian. Looking at a rainbow colored box (green, white orange/red) box of it right now .. . The newer stuff now comes in a black & blue box. The ammo was initially produced to Russian specs back in the early cold war days so perhaps that is where the belief comes that it is Russian???
In either case I have used it in various calibers (both pistol and rifle) and have found it to be no better or worse than anything else you can get.
And a clip from the company web site....
" ... The foundations for the operation of the company were laid by Mátravidéki Fémmûvek established in 1952. The company based its production on the conventions of ammunition manufacturing in Hungary..... they started to produce for the civil market in the late 1950's....The policy of MFS Hungarian Ammunition Manufacturing Inc. is to ensure high quality....we constantly update and develop manufacturing technology as well as used basic material and broaden the product range. The ever-wider range of products, our integrity and top quality are the keys to our success, which is reflected in the increase of sales and clientele....."
Regards,