It's important to note that the practice of sending outdated ammunition as military aid isn't unique to this situation. For example, Ukraine has also received old ammunition, dating back to the 60s but refreshed with new fuses. This approach not only clears out warehouses for new production but is also significantly cheaper than disposal.
This situation further supports claims from Russian artillerymen who regard the DPRK's ammunition as inferior, even worse than their own or Iranian munitions. Concerns are particularly raised about the powder charges, which offer half the range and are remarkably unstable compared to those of competitors.
The unpredictability of the shell's range greatly hampers accurate firing. Furthermore, DPRK ammunition is notorious for its high rate of failure upon use.
These issues, coupled with the relatively unimpressive performance of Russian artillery systems compared to Western equivalents, paint a grim picture. For instance, the 122 mm caliber shells, with about 5.5–7.7 lbs of TNT, have an effective range of up to 9 miles, and 152 mm caliber shells, containing around 17.6 lbs of explosive material, can reach up to 11 miles. This is significantly less than the 15 miles achieved by NATO's short-barreled 155 mm caliber guns, such as the TRF1 howitzers.
Despite DPRK's ostensibly more generous support to Russia compared to EU countries’ assistance to Ukraine, the low quality of this support leaves much to be desired. Ultimately, it appears that Kim Jong Un benefits the most, exchanging undesirable stock for relatively modern technology.