As he is the father of all MGs.
And Kalashnikov didnt invent shyte.
His weapons are good, but are in fact puzzles of other weapons..
And whole concept is a rip off from STG 44/45 etc..
(and trigger assebly is about 100% Garand.. for starters..)

*Edit*
Aimo Lahti,
While he designed score of good weapons (and quite orginal ones..) they really didnt have that large influence over anything..
Only SUOMI M31 KP had (Finland SMG Model 31..) As Finnish use of those in winter war showed the rest of the world how good SMGs are for military use..
(and everybody started to use those on much larger scale..) also the design of SUOMI had great impact on Russians.. after all, they did copy it and
produced it AS PPSh-41 and also SUOMI SMGs 71 round drum was directly copied by russians and used in those PPSh-41s..
But still my vote goes for Hiram Maxim.
[Edited on 10-12-2003 by FULCRUM]