But arms experts say a drawing on the base of the statue shows the StG 44 rifle used by the Nazis during WWII.
They say this will be now corrected.
"A mistake has been made by the sculptor, and he is already there dismantling this plate with the StG drawing," executive director of the Russian Military Historical Society Vladislav Kononov was quoted as saying by Russian news agencies.
The society commissioned the 7.5m (25ft) monument, which shows Kalashnikov holding an AK-47 in his arms.
A series of modified AK rifles are etched on a metallic plate on the base of the statue, including the wrong drawing.
Russian arms historian Yuri Pasholok was the first to point out the error, and several experts later confirmed this was the case.
Sculptor Salavat Shcherbakov said on Friday that "this is something we're correcting", adding that "we're trying to avoid mistakes", Russia's Rossiya-24 TV channel reported.
The automatic rifle is one of Russia's most celebrated weapons, with Culture Minister Vladimir Medinsky describing it as the country's "cultural brand".
Designed by Kalashnikov in 1946, it became one of the world's most familiar weapons used in virtually every major conflict.
Its comparative simplicity made it cheap to manufacture, as well as reliable and easy to maintain.
Although honoured by the state, Kalashnikov himself made little money from his gun. He once said he would have been better off designing a lawn mower.
He died in 2013 at the age of 94.
The StG-44 (Sturmgewehr 44) was invented by Hugo Schmeisser and first used by Adolf Hitler's troops in 1944.
Some experts point to the similarity of the StG-44 and the AK-47, and also mention the fact that Schmeisser - together with a group of German engineers - was forced to work in the Soviet Union after World War II.
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