What rifles are similar to AK-47's?

Answer 1

The AK-74 and the SVD both work on the same piston driving operating system as the AK-47 but fire different types of ammo.

Actually, the SVD differs in that it uses a short recoil system, rather than the long recoil method of operation.

AK variants are countless, and are naturally related. Some countries which did not adopt the SVD developed their own designated marksman rifles, which did use the same method of operation as the AK - most prominent of these two would be the Romanian PSL and the Yugoslav M76. The M76 was manufactured in 7.92x57 for the JNA, but export versions were offered in 7.62x51 and the Soviet 7.62x54R (the latter of which was manufactured under licence in Iraq).

Aside from those, the Galil is derivative of the Kalashnikov, as is the Indian INSAS rifle. The Belgian FN-FNC and Mexican FX-05 rifles also use an operating system based at least partially on the Kalashnikov.