Hmmmmm.
The Moisin-Nagant rifle used 5 round stripper clips.
The SKS and AK-47 ammo (and I suppose AK-74 ammo) comes on ten round stripper clips.
I'd say it has something to do with the size of a Soviet rifle squad. One can "feeds" one squad, each trooper gets X number of rounds.
Either that, or the can came first.
"Okay-dokay Comrade Private. If you are putting rounds in can like so, you can get 440 rounds into heroic can of People's Army."
Bureaucrats are pretty much bureaucrats.
Just remember, this guess is worth at least double the purchase price.