Neither the Tsarist Russians or the Soviets ever adopted the Federov as their standard rifle. Only 5,000 were ever ordered by the Tsarist government, and even with the post-war production that ended in 1925, only about 3,000 were ever actually made.

It wasn't suitable for use as a standard infantry rifle for several reasons.

1. It fired 6.5mm Japanese, rather than the more widely-available 7.62mm Russian - this was why the Soviets eventually canned it.

2. It wasn't really a infantry rifle, but worked better as team-served autonomic rifle like a BAR or a Chauchat.

3. It was expensive and difficult to make - I've written quite a long answer here about how screwed up Russia's arms industry was in WWI. The Russians in WWI couldn't make enough Mosin-Nagant rifles, so making a large number of complicated self-loading rifles was a pipe dream. The same issues were present in Soviet Russia in the Civil War and the 1920s.

As for why the Soviets didn't have more auto-loading rifles by WWII, we have to consider the gap between goals and realities. Nearly every military wanted semi-auto rifles in the late 1930s, they just couldn't get them, for a huge number of reasons. This answer has more details on why countries were slow to get self-loading rifles and how WWII itself actually killed semi-auto rifles around the world.

Before i answer your question: Ian Mccollum of forgotten weapons released a video on the Federov this christmas, he goes into the history and the mechanics of the rifle. Thought it might interest you.

Now for your question:

1. 7.6254R was the standard ammunition of Russia at the time(and is still used in modern machineguns), the fedorov was originally chambered in a new 6.5 fedorov cartridge. Russia however had some japanese arisakas(bought from the uk) and they decided that the fedorov had to be rechambered in 6.550 arisaka. Something that always causes hiccups/problems, as they would now need to produce new 6.5*50Arisaka(the existing stockpile would be gone relativily fast if they produced new fedorov's and used the japanese rifles).

2)The Federov was never suited to be a standard infantry rifle, the rifle is simply not grunt proof(read idiot proof). The rifle is a bit fickle , and needs alot more care/maintenance than your average soldier is able to give it(in this time period). No one had experience with fielding large numbers of selfloading rifle's let alone select fire rifle's. The rifle however would be perfectly suitable as a specialist weapon, give it to the more capable shooters/soldiers of the squad. They can care better for it and can leverage the increased fire power better. You could also press it into a lmg role, albeit with limited succes as the barrel is a bit light for it and it does not have a bipod.

3. The rifle is simply way to expensive to manufacture, a standard infantry rifle has to be able to be mass mass produced. The federov needs a lot of machining time, all that steel milling takes a lot of time/money. Something that Russia did not have in this period(there are alot of good answers that go into this on this subreddit). Just look at the simplification of russian smg's during ww2, they needed more guns and simplified designs/started using more stampings instead of milling in the new guns. The design of the fedorov does not lend itself to optimising it very well.

4)Purely mechanical the rifle has it's problems too. The rifle operates with a short recoil action( The barrel and the action move backwards after firing for a short duration, after which the action continous and the barrel resets).For shoulder fired weapons it is simply inferiour to gas operated systems, like the ones used in the m1 Garand or the svt-series. It is certainly usable , but it's the combination of a short recoil action and those weird sidelocking plates, that cause the fedorov to be a technological dead end. A lot of modern rifles use a derivative of the short stroke gas piston(svt series), none use the weird side locking fedorov action.

The Fedorov had the problem of being the first of it's kind/ahead of it's time. This caused the rifle to be to complicated both in use and in production, if it had received more time maybe it could have been improved. But i very much doubt it , as other nations struggled with adopting selfloading rifle's that were much better suited for the job.