History Question:

When was it that M. Kalashnikov (or was it someone else) decided to incorperate a rate reducing mechanism on the AK design? What prompted this? Misfires? Timing issues? Barrel heating, ect? I love to learn everything I can possibly learn about things that interest me and haven't found a direct answer to this question yet... only speculations.

His original patent does not include this FA part so I assume it was post 1947. But WHEN and WHY is what interests me.

If anyone can give me a date and a reason, I really would appreciate it. Links and/or references, even better... ;)

the mechanism isn't a "rate reducer" it doesn't reduce the rate of fire, but rather is a hammer release delay device that was one of the improvements when they redesigned the AK-47 into the AKM

Thanks for clearing that up for me, 16r40. I was under the impression (incorrectly) that it actually decreased the rate of fire somehow. So, in actuality, it simply delays the hammer so it cannot 'ride' the bolt back to the chamber on a fresh round...

Interesting.

In a full auto AK that doesn't happen with or without the hammer retarder. The auto sear holds the hammer back until the carrier travels fully forward, at which point the sear pulls free of the hammer and it can snap forward. The hammer retarder delays this snap forward slightly. Any way you look at it, this added delay reduces the firing rate slightly. Whether or not this was the purpose of it, or simply a side effect is unclear.The reason they added the retarder is the subject of some debate, ask 5 different people why it's there and you get 5 different answers.

The reason they added the retarder is the subject of some debate, ask 5 different people why it's there and you get 5 different answers.

That's precisely why I asked this question here... [shrug]. Thanks for your reply, KernelKrink. I figured if you guys didn't know for sure, nobody short of Mikhail, himself, does. ;)

my japanese book on the AK, just indicated that the AKM had a more reliable mechanism over the AK-47. probably more to do with it in full auto fire, then semi auto....since that is the primary reason for which it was designed, to deliver volume of fire vs semi auto fire.....it could be a variaty of reason, going from a milled receiver to a thin stamped sheet metal might be one.....the chinese don't use a delay mecanism in their variants, not that I'm aware of....but their receivers are much more thicker. just pick a theory.....it's as good as the next

"More reliable" is my personal favorite of all the theories I've heard so far. That particular one states the thin sheet metal shell coupled with the hardened trunnion mounted to it causes the bolt carrier to sometimes bounce off the trunnion slightly, and without the retarder to slightly delay the hammer fall the hammer can hit the carrier instead of the firing pin, causing a stoppage.

Then there's the one that says the cyclic rate without the retarder is the perfect frequency to set up harmonics in the sheet metal that causes it to crack and loosen the rivets. The retarder changes the cyclic rate to a different frequency and now they last as long as the milled. Kinda interrelated to the bounceback above, some versions state that the "tuning fork" effect is what causes bounceback.

Those seem to be the most plausible two anyway.

It does appear to be there to keep bolt bounce from causing misfires.It does reduce the rate of fire but only a tiny bit.Nothing serious.It is odd though that the AK74 has it but the krink has a fake one,only acting as a spacer for the rest of the parts and doesn't delay the hammer.

Take the sear spring out of your ak and try to fire it. the hammer will ride the bolt till it closes and it wont fire. by delaying that the hammer can strike instead of ride. though i did forget the sear spring on one of my earlier builds and had 3 rounds go off like an uzi. couldnt get it to do it again though.

AK-47 funkce závìru zpomalenì (1,7MB) (http://jardax.ethernet.cz/Gun/Video/ak47_slow.avi)
here is a great full auto in slow mo.