The impression that I get is that no "expanding" bullet with a steel jacket gives any kind of consistent or reliable performance in ballistic gelatin in this caliber. I base that on tests like these.
https://www.youtube.com/watch?v=H6RVuISLJ3ohttps://www.youtube.com/watch?v=v15hknRziWEhttps://www.youtube.com/watch?v=BOHrY9KiR2AI speculate that this may be at least partially partially because steel, which the Russians use for bullet jackets because it's less expensive and more plentiful for them than copper, is much harder and tougher than copper. Bullets with steel jackets may only expand if that production lot of ammunition gets over a certain minimum velocity from the muzzle, and with the Russian export 7.62x39mm you are rolling the dice on whether this batch is pushing 2500 ft/sec or barely breaking 2050. Small differences in the thickness of a steel jacket might also make it much more or less likely to expand at a given velocity, just because steel is so much stronger than copper. At least some of these steel-jacketed expanding bullet designs seem to be dependent upon cuts or grooves on the inside of the jacket near the point, number, length, and depth of which can vary significantly from batch to batch, if they are even present at all. Maybe it expands, maybe it doesn't. Maybe it yaws significantly, maybe it doesn't. They are great when they work as advertised, but that's a sometime thing. You can do better.
As I once heard a guy on the Internet say, that doesn't mean these steel-jacketed softpoint and hollowpoint bullets are Nerf darts. They're not going to bounce off the bad guy's chest. But it seems to be questionable whether they'll expand dependably. They do not seem to be consistent.
I wish the Russians would use copper for the bullet jackets, at least on the softpoints and hollowpoints. But it's not like they're having any trouble selling the ammo the way they make it right now.
Sellier & Bellot 7.62x39mm softpoints have copper jackets and give excellent performance at 7.62x39mm velocities. Pre-panic, they were around 45-50 cents per round.
https://www.youtube.com/watch?v=H6RVuISLJ3oPrvi Partizan makes a very similar load at the same price point, also using a copper jacketed softpoint bullet. However, I have never seen any kind of test with it. If you look on the Internet you will see some posts on outdoor forums from people who shot deer or hogs with them and said they worked, but gave no details.
Generally around the same price per round is Hornady's steel-case 7.62x39mm hunting ammo using the SST bullet with the polymer tip, which also seems to be a very good, very consistent performer in the tests I've seen.
https://www.youtube.com/watch?v=_Jn6GiiVrcMFederal Fusion was $1+/round even before the panic, but the bullet also seems to perform pretty well.
https://www.youtube.com/watch?v=xEo6avZd9ysDocGKR said he got good results with Winchester Super-X 123gr softpoints, Lapua softpoints, and the old Hornady VMAX load that with the discontinued 123gr VMAX bullet.
Speer catalogs a 7.62x39mm load with a 123gr Gold Dot softpoint, but I have yet to see a gel test with it.