The thing about russians is that they get the superfast fireing machineguns ALONG with devastating cannons.
Which is in no small part balanced by this:
Yak 7B: 1x 20mm, 2x 12.7mm
Yak 1B: 1x 20mm, 1x 12.7mm
Yak 9T: 1x 37mm, 1x 12.7mm
Yak 3: 1x 20mm, 2x 12.7mm
LaGG-3-66: 1x 20mm, 1x 12.7mm
La-5, La-5F, La-5FN, La-7: 2x 20mm
etc. etc.
Seriously, they're all amazingly undergunned, with very low ammo. The only Russian fighter I have with something approaching a respectable armament is my I-16 type 28. Pretty much every US/British/Japanese fighter above T2ish has something like 2xmg, 2x cannon/x4mg/6xmg/8xmg/4x cannon/4x mg, 1x cannon/6xmg, 2x cannon/etc., all with deep ammo pools.
And amusing = Instantly losing one or both of your wings, entire tail at least one gunner AND your pilot in the timeframe of less than 2 seconds.
And the fact they are "only" 20 mm does not make a difference if they seem to be infused with demonic warp energies.
News flash: Any plane with a cannon can do that. Even in arcade, landing a couple cannon shells in the right places will completely trash a plane. It also depends on which sort of shell hit you; a HEF-I will usually hurt a lot worse than AP-I.
On a related note, that's part of the reason why a lot of us like HB: Less bullshit. If you hit someone with a cannon shell, 80% of the time they're dead, period. 20% of the time you'll need a second shell or burst of MG fire to finish them. You can hit someone with 10+ cannon shells in AB and if the RNG isn't feeling kind, they'll limp away to base.
It's as was said earlier, though, the Russian fighters aren't particularly good at anything, they're just also not terrible at anything, so assuming poor pilots in a Russian fighter and in something else, the Russian will usually win because the other player doesn't exploit their advantages (e.g. a US pilot trying to turnfight in a Kittyhawk instead of doing the closest you can get to a boom-and-zoom in arcade/a Japanese pilot trying to outrun them)