Ukraine artillery M777 howitzer
Ukrainian troops fire a M777 howitzer near Zaporizhzhya on July 16.
  • Ukraine has amassed a polyglot arsenal of artillery thanks to donations from its foreign partners.
  • Those howitzers are a key source of firepower and have battered Russian forces to nearly 18 months.
  • But sustaining and maintaining each kind of artillery presents a problem for Ukrainian troops.

Artillery has become Ukraine's deadliest and most prolific weapon against Russia. One reason for that is Ukraine's army has managed to integrate more than a dozen kinds of Western guns into its pre-war arsenal of Soviet-era cannons.