Ignorance is a bliss...
Yesterday I get an email from a gun company that makes AR stuff and they have a sale on pistol uppers on 7.62 x 39 AKA 7.62 Russian at a very nice price. I imagined it was a way to seduce you into buying an special AR lower just like many try to do with the 9mm ARs (a nasty experience I shan’t repeat anytime soon) because it will have to be designed to take AK mags.
And then clicked on the video. Nope, seems to be standard AR and… standard AR mags? Are you effing kidding me? AR mags will take 7.62 Rusky?
Apparently so.
I have two stripped lowers and at least all the internals to build one to completion. You know what happens next…. yes, how do I sneak this past the Missus because an AR Pistol that speaks Russkiy is something I must have and she already gave me the stink eye when I mentioned it.
Mmm... You might want to check on those mags, Miguel. Just because they can fit a cartridge doesn't mean it's going to work properly. (Paging H&K...)
There are magazines designed for the 7.62x39mm cartridge, that will fit in an AR magwell. For instance, E-Lander, ASC, Duramag. (Please tell me I don't have to make a comment on the ProMags.)
E.g. https://gunmagwarehouse.com/all-magazines/rifles/magazines/ar-15-magazines/7-62-x-39mm
Part of the issue is the feed lip spacing (the 7.62 has a wider base than the 5.56); but another part of it is the magazine curve. The 7.62's case has a rather dramatic taper, so past a certain number of cartridges they will not play well in magazines designed for the 5.56's much smaller taper, even if you can insert them.
I can't speak to the E-Landers in 7.62x39mm directly, but I use their 6.5 mm Grendel mags - so, same parent case as the 7.62 - for AR lowers and they've been great. A little on the heavy side, but very reliable.
Apparently AR15Discounts are having a sale on the E-Landers they carry, in addition to their Memorial Day sale:
https://ar15discounts.com/products/e-lander-7-62x39mm-17-round-steel-ar-15-magazine/?avad=74383_d41c2ee4d
And here's a general search using AmmoSeek:
https://ammoseek.com/magazines/7.62x39mm?ikw=AR-15
Soooo, what can you bribe her with?