Technically the longest-serving assault rifle is the Stg44; its still used by militias and insurgents across the Middle East and the Horn of Africa, but yeah, in terms of quantity, the AK-47 is. Meh, it'll probably remain in service till bullet-firing weapons become obsolete; I mean, look at the M1911; its 100 years old this year and still a widely used firearm because it does its job really well. There are lever and bolt-action designs that still see widespread use as hunting weapons, even though they probably pre-date all living people.
The Kalashnikov-pattern works really well and I'd be surprised if the Russians choose a weapon to replace the AK-74M with a weapon that isn't a derivative; I was surprised when the Chinese did.
The Kalashnikov-pattern works really well and I'd be surprised if the Russians choose a weapon to replace the AK-74M with a weapon that isn't a derivative; I was surprised when the Chinese did.