Its a 5.56 or 5.45, likely a Saiga with Magpul furniture. The milled AK-47 doesnt have the dimple but the stamped AKM does for mag stabilization. Its not a 7.62x39mm because the magazine is not curved enough.
The hand grip is a US Palm battle grip, the but stock looks like a magpul zhukov and the for end is definitely not a magpul it looks more like the stock from a Saiga IZ 240 AK 74 Rifle. As a matter of fact the Saiga is sooo close but the trigger is too far to the rear.
It’s not a 5.56.
It’s 5.45. Look at the Tapco 5.45 mag here:
http://www.midwayusa.com/product/1116145922/tapco-intrafuse-magazine-ak-74-545x39mm-russian-polymer
Tapco doesn’t even make 5.56 mags.