My favorite upper - Wolfpack Armory Side Charging Stripped Rifle Caliber Upper Receiver

I got mine from Wolfpack I had them custom cerokote and milled to be compatible with (7.62x39)AKM Mags and their AR-47 lowers. The side charger make all the difference, it doesn't move or reciprocate while shooting, and it is very handy to charge. I swapped barrels and my gas port and gas block weren't lined up, and with the side charger it wasn't that big of a inconvenience I just racked it back like a bolt action to cycle it in-between rounds until I got my optic zeroed that day. Not a big hassle. The only downside to this upper is the weight, because it's milled out of 6065 and not forged and it a bit chunkier, but that's to be expected. I was able to get my entire rifle with optic (Primary Arms 3x Prism, light, furniture down to 7lbs by swapping the Heavy barrel adding a Faxon Russian Gunner (7.62x39) 16" barrel, Trybe Magnite Magnesium M-Lok Handguard (looks very similar to the one that came from Wolfpack). The only other thing I think could make my 7.62x39 rifle would be to have a piston driven action instead of DI as many types of 7.62x39 are dirtier (com-bloc steel cases), versus the cleaner Serbian and Bosnian brass cased. Just my two cents. Turned out being a much nicer rifle than the CMMG MK47 and not as expensive.