“Several factories in North Korea have altered their production processes to quickly churn out 152-millimeter artillery shells”
North Korea is no South Korea, when it comes to producing anything. They no doubt have a small Artillery shell production capacity, compared to that of Russia itself.
What North Korea does have however, is one of the world’s very largest stockpiles of old Artillery shells. They can produce some shells (maybe Russia pays more for the new production), but the bulk of what Russia has been getting (and can get) from North Korea, were produced or acquired by Grand Daddy Kim.
12JAN2024 What gunners don't have in abundance are howitzer barrels. And there's evidence the Russians are maintaining their best guns ... by dismantling their worst guns.
A howitzer barrel usually is good for a few thousand shots before its steel becomes brittle or bends. If an artillery battery doesn't replace worn-out barrels in time, it risks catastrophic accidents as shells explode inside their guns. Something we've seen many, many times on both sides of Russia's 23-month wider war on Ukraine.