La-5 Hub Cannon?

[Phoenix3107]

Why is there a cannon mounted inside the engine prop of the La5, when there are two nose cowl guns to kill stuff with? Does it have anything to do with armament whatsoever, or did they simply forget to put ammo inside of it?

[Karnak]

The La-5 does not have a cannon in the hub of the prop.  You may be looking at the engine starter and mistaking it for a gun.

[Greebo]

As Karnak said, the spinner shaft is part of a starter mechanism. In WW1 the British began using a Hucks starter truck to get aircraft engines going. By WW2 they used other methods, but the Soviets still used this system. I guess this helped when the weather was really cold. Here's a Hucks starter in action:

[MiloMorai]

One can see clearly the 'dogs' for the starter shaft.