Working on your AK can be tricky with you are trying to wield a 2 pound sledge in one hand and a cutting torch in the other… just your standard AK armorer’s tools. You can’t grow a third hand (easily) but you can pick up an AK-47 Armorer Block from CROSSTAC. Their AK Armorer Block locks into the AK’s magazine well tight so that you can clamp the block into your bench vice.
I solved this problem by re-purposing a crap magazine(hey, it happens) with a wood block insert so it clamps firmly in vise.