Fucked up and got 7.62x39 ammo today and well said to far to go back to the store.
https://sandersarmoryusa.com/product/ar47-16-7-62x39-complete-upper-assembly/
Ordered that and a pmag instead. Lol 299 for a complete upper? No brainier if I say so myself.
Here's the thing,though. If you weren't going to buy it anyway then you're not actually saving money, you're just spending more. You didn't save dick.