There have been reports that Russia have been buying artillery from North Korea. Now, I was wondering what are the other means for Russia to buy ammunition and artillery from other sources? Are there independent arms traders, or other countries that could be potential sources for artillery and ammunition, or is it just North Korea and Iran, both of which are heavily sanctioned.
The Soviet Union was a major arms supplier: it provided weapons to the Warsaw Pact countries and many Soviet-aligned and neutral third-world countries (look at, for example, the operators of the T-72 tank or the D-20 howitzer).
Most of Russia's military equipment is either this Soviet equipment, or is derived from it. This presents a serious problem: most of the other countries that use this equipment are either incapable of building it, or are not inclined to sell it to Russia. Russia is purchasing things from Iran and North Korea not because they are similarly outcast, but because they are two of the very few countries that produce their own Soviet-compatible military equipment.
Other countries that use Soviet or Soviet-derived hardware and have a non-trivial manufacturing base are China and India, and although neither of them is fully cooperative with Western sanctions on Russia, neither is willing to defy those sanctions to the point of supplying Russia with military hardware (and in the case of China, the Sino-Soviet split means that much of its hardware is only distantly related to Russia's hardware).
As a partial answer, you mentioned "independent arms traders." They don't really exist at this scale.
When companies in countries want to sell arms, those countries want to make sure they know where the arms go. There will be export regulations, traders will demand to see end user certificates, and that will be monitored. (For instance, Germany could promise German AA tanks to Ukraine, but their remaining ammo was Swiss-made, so they had to look for other sources first.)
There is a certain amount of illicit trade, circumventing end user certificates and export controls, but that is mostly Small Arms and Light Weapons or obsolete technology.
I mostly want to make one thing clear: Russia builds most of their weapons itself. That's kind of the point of being a super-power, even one which has been in decline for some time.
The notion that North Korea could make much of an impact on Russia's capability by weapons deliveries is absurd. Iran is much more capable, but still far below Russia's own production capabilities.
Russia does import dual use goods and general industrial goods to support its weapon production, and they used to buy those goods wherever they wanted: The USA, the EU, China, famously neutral-as-long-as-it's-good-for-business Switzerland, etc. The goods so imported might directly go into a weapons system - for example drones shot down in Ukraine were found to contain lots of off-the-shelf western components.
I don't think anyone knows right now when and if Russia will be able to easily buy western high tech components again (could be a single year, could be after a regime change in 20 years...), but China and some quickly industrializing other countries are happy to pick up the slack as good as they can.
The Russians have only 4 option to acquire Equipment and Ammunition.
- Manufacturing & Production.
- Take from long term storage.
- Buy back from countries to whom you previously sold you own equipment & ammunition.
- Buy new equipment from friendly countries.
Let's take a quick look at each and every one of them
Widely reported difficulties to obtain parts will decrease production. Even if the sanctions did not have a negative result, Russia would still not be able to produce quickly enough to replenish losses.
Russia is known to have huge storage facilities with old weapons, equipment and ammunition. And they are trying to take out as much as they can, as quickly as they can. However, the storage conditions are bad at best and much equipment and ammunition is old, outdated and unreliable.
They can approach countries whom previously purchased Russian equipment and ammunition. Some will help them out such as North Korea. Some former USSR satellites in central Asia may want to help as well. But in general most countries, including China and India, will be very hesitant while contemplating possible sanctions that may come as a result of this.
And than of course they have the option to buy new equipment from any country who is willing to sell to them. The recent sale of drones from Iran to the USSR is a good example of this, but also shows the issues that come with this. These Iranian drones have reportedly many issues and are very unreliable. This option 4 also introduces new issues with maintenance, training, spare parts, and experience.
So in short, I think the Russians have options, but none of them are good. Add to this the growing isolation because of hampered supply lines and destroyed storage facilities and I can see why it has been reported that Russia is having a rough time down there right now...