An artillery strike in MnB:Vietnam is similar to arty in MnB 2. It fires 5-10 shells to a designated location. Artillery is very effective against VC and can cause large destruction on big clusters of enemies. It is also effective against bunker and can kill or seriously injure men inside it. It is best used ahead of large enemy forces as they will attack directly to the zone the artillery is incoming upon. This is one of those weapons you should use against enemy positions inside base that rangers or other high observation soldiers have found. Be careful, shots may miss the target and cause friendly fire if you have troops too near target area.
The VC also have this, luckily it comes pretty rarely. The bad side is that it's very inaccurate and often lands inside the base.