Russia is trending toward empty when it comes to their military inventory and they won't be able to replenish it as things stand. The only way they can is if China steps in and provides an epic scale infusion (which is not in China's interest).
Meanwhile the US can rev its military industrial complex to an extreme degree as it sees fit; and in tandem with Ukraine, obliterate Russia's military to the extent the Russians are dumb enough to continue occupying Ukrainian territory and sending more of their soldiers and hardware to the slaughter. The US hasn't even begun to seriously rev its production capabilities.
The equation there is Russia is fucked. Their national strength derives from energy + military power / power perception - one of those is heavily destroyed (courtesy of Ukraine's military + NATO weapons + sanctions).
Russia is so incompetent and drained they're having to source drones from Iran and go begging to North Korea.
"Russia’s budget surplus evaporates as energy revenues shrink"
https://www.ft.com/content/d9cdc51f-5fe3-4f4a-b0e8-054ef21a2...
> Russia’s budget surplus for 2022 has almost evaporated after a sharp drop in energy exports during August led to a monthly deficit of as much as Rbs360bn ($5.9bn).
Russia is increasingly cutting itself now too:
> Revenues look set to worsen following Russia’s suspension of Nord Stream 1, one of its main gas pipelines to Europe, in early September.
> Russia’s economy shrunk 4.3 per cent in July 2022 compared with the same month a year earlier, according to the country’s economy ministry. Analysts at Aton, a Russian brokerage, expect the economy to contract by a further 5 per cent in 2023 because of falling energy output.