AK 102 5.56x45 NATO rifle.
IMPORTANT Read the instruction - weapon has a lot of features.
Its more like a model rifle, a compromise between realism of operation and reliability, and it uses exactly the same locking & gas operation like my shotgun.
It likes to explode and misfire, also spent case ejection works like crap. It's nowhere near as reliable as the real AK.
To shoot:
1. Pull the mag in. (mags are refillable, due to the lag there are only 15 cartridges, 5 in the mag and 10 outside, you can load full 30 if your computer can handle it)
IMPORTANT - mags are AK like, so you have to put it right side first, and then swing it up to lock it. If you don't know what it means, just watch some movies of AK reload.
2. Turn the safety off. (weapon cannot be cocked with safety on - just like real AK)
It has 2 fire modes + safe, lowest setting is for semi-auto.
3. Cock the weapon.
4. Pull the trigger. (its safer to just push the return/enter key) Try to throw away spent cases if they land close to the bolt, they can easily jamm it.
5. If the mag is empty, remove it using mag release lever.
Weapon can be disassembled just like the real AK (including gas tube, only trigger group and bolt group cannot be disassembled, cleaning rod cannot be removed), so watch some movies if you want to know how to do it.
Big thanks for DualDesertEagle for making the video.
. The little throwaways like adjustable sights make weapons infinitely better.
Do it better next time. (You should try making a Glock with dissassembly features, that would be really popular) 
