Unless things have changed, that cut is already there. It's covered by a plate you remove.
I did my Saiga 12 a few years ago and I'm no gunsmith. The 7.62 x 39 shouldn't be that much harder.
I got to the McDonough Walmart early this morning and got the last one. Thanks for the heads up!!
I had to deal with the ABF but it was worth it as I wanted one to build and these suckers are rare plus I refuse to pay the up charge of the free market here.