During World War 1, Russian military gear seems to have lagged significantly behind other major powers. However, by the end of World War 2 Russia had designed and built a very effective tank and air forces, and would eventually produce large rockets, nuclear weapons, advanced aircraft and surface-to-air missiles after the war.
Not only that, but I see a trend where Russian gear tended to be effectively designed versus other countries gear. The T34/85 was simpler and easier to build/maintain than German tanks like the Tiger, while still being formidable. The AK-47 (and derivatives) has a reputation as being much more reliable than the American M-16 in Vietnam. Russian rocketry upstaged American efforts until the moon landings, and they were able to master staged combustion earlier than the US as well.
How did Russia go from lagging so far behind in weapon development in World War 1 to having world class engineering after World War 2? Why wasn't that talent evident in World War 1?
Russias problems in the WW I were about quantity of its armaments, not quality - it stemmed from a underdeveloped industry and effective blockade after the Ottomans joined the war. The technical aspect itself was well-developed. To relate to two of your examples, Fedorov avtomat was one (if not the) of the first of its kinds, and the father of rocketry, Ciolkowski, was Russian.
Much of the Soviet Union's equipment was outdated at the start of the WWII. Most of their aircraft were obsolete, most of their tanks were outdated (only a small percentage were T-34's and KVs), and their artillery lacked modern fire control.
The Soviets had been able to see the deficiencies of their BT series tanks and T-26's during the Battles of Khalkhin Gol and the Winter War in 1939. Among other things, their Petrol engines easily caught fire compared to diesel engines. This prompted the development of the T-34.
In general, war advances war technologies.
The end of WWII prompted the Cold War. Both American and Russian technologies benefited from acquirement of German technology. More importantly, both sides began pumping billions into military technologies for the ensuing.