It does take some skill to drill the holes in the correct place and the correct size so when complete it does NOT look like any 12 year old kid in Africa built the AK!
I have built over a dozen and it does take time to ensure that it comes out looking and functioning properly. I also have an auto shop with proper equipment. (20 ton press, drill press, small lathe etc.)
Squeezing or pressing rivets 'crooked' will ruin the look and spoil your day!
Populating the barrel takes some skill with an end mill in a drill press or mill.(drill bits don't work)
Yugos are a little harder on the tiny 2.5mm pins vs the 3mm pins of the regular AKs.
The 3/32" carbide end mill snaps easily if you get in a hurry.
Then ream to 2.5mm, insert pin.
Not hard just go slow and have the right equipment.
Trying to get a drill to 'bite' on the top of the curved barrel will deflect the bit and won't go straight through.(it might even snap)
Drill bits points are either 118 degrees or 135 degrees and the barrel is curved so the two angled surfaces (drill point and curved barrel) cause a heavy side load.
Drill bits work best if the drill point is perpendicular to the work. The drill bit point in a barrel component never touches the barrel until it is almost halfway through.(just the edges of the drill bit)
Large drill bits are probably fine as they don't flex much.
I use square end carbide 'end mill bits'(4 flute) and go VERY SLOW until the bit has carved away enough material that it does not have side forces to deflect and drift away from the hole already in the barrel component.
I still damage end mill bits, especially the very small diameter ones.
The small diameter ones I buy in packs of 10.(carbide is BRITTLE)
The cutting edges chip or the bit 'shatters'.
You need Collets! Even a mill with a drill chuck won't be as accurate and a mill with a collet! I did 10 or so ak rifles with a drill press. It's not as easy as a mini mill. It can be done if you can go slow with the drill press. People with out power tools re build ak rifles in straw huts and in caves. In this country we have an amazing power grid and good paying jobs and credit. You should be able to build and ak you want
It's not the plane it the aviator.