BAKHMUT, Ukraine — Ukrainian soldiers ran around a shell in a field on a recent morning. In a flurry of activity, a man sent a 106-pound shell from a truck into the gun. Another, using a wooden pole, pushed it into the breach. “Loaded!” cried the soldier, then knelt on the ground and covered his ears with his hands. The gun fired with a thunderous boom. A cloud of smoke rose. Leaves were thrown from the nearby trees. The shell sailed toward the Russians with a metallic screech. It’s a scene repeated thousands of times daily along the front lines in Ukraine: artillery duels and long-range strikes by both sides on targets ranging from infantry to fuel depots to tanks. And what followed the salvo fired Wednesday morning in eastern Ukraine was also indicative of the tempo of this war: a coffee break. This is a war fought in a cycle of opposites – bursts of chaos from outgoing or incoming bombardment and then long lulls in which soldiers go about their most mundane activities. Fighters who moments before unleashed devastating weapons with a thunderous roar settled in a grove of oak trees around a picnic table with wooden boxes of ammunition, boiling water on a camp stove and pouring cups of instant coffee. They rested in an oak forest, overlooking a field of tall green grass and purple flowering thistles. Elsewhere, soldiers used lulls to smoke or get a haircut. A Ukrainian soldier getting a haircut at a forward base in the frontline city of Bakhmut. Credit…David Guttenfelder for The New York Times On a recent visit, soldiers of the 58th Brigade fighting in and around the city of Bakhmut, where the artillery war is raging, attacked and were attacked by artillery. In the rolling, grassy hills west of Bakhmut, puffs of brown smoke rose from incoming Russian strikes, aimed at Ukrainian artillery positions. The critical importance of long-range fire was one reason the United States and other allies rushed NATO-caliber shells into Ukraine. Its military is close to exhausting its entire stockpile of Soviet-legacy shells in its own arsenal and from allied countries in Eastern Europe, and is now turning to more abundant NATO munitions. Russia has a huge stockpile of artillery ammunition, but there are signs that it is dipping into older stockpiles that more often than not explode on impact. The Soviet-legacy howitzer fired by the Ukrainian team, a model called the D-20 called the “fishing lure,” held up well, said the commander, Lt. Oleksandr Shakin. American-supplied long-range weapons, such as the M777 gun and the high-mobility artillery rocket system known as HIMARS, have extended the range of Ukraine’s military, but most of the arsenal is still Soviet-era artillery. A Ukrainian artillery crew at work near Bakhmut.Credit…David Guttenfelder for The New York Times The cannon they fired was made in 1979, he said, and most of the shells were from the 1980s. Still, Lt. Shakin said, “They haven’t let me down yet.” Typically, he said, he fires about 20 rounds a day from each gun, keeping Ukraine’s dwindling supply of 152mm ammunition. “We have a lot of motivation,” said Captain Kostyantin Viter, an artillery officer. “In front of us is our infantry and we must cover it. Our families are behind us.” Inside the city of Bakhmut on Wednesday, at a position where soldiers of the 58th Brigade stand guard in an abandoned municipal building, the whistles of their colleagues’ shells could be heard flying overhead — aimed at Russian forces in the east of the city. A blocked and mostly deserted street in the center of Bakhmut.Credit…David Guttenfelder for The New York Times The soldiers stood in a courtyard, smoking and listening to the whistling of shells overhead and the concussion of explosions in the distance. The hum of electric clippers also filled the air as one soldier clipped another. A few trucks were parked in the yard and a dozen or so soldiers were milling about. Half an hour later, a new noise joined the background of distant explosions: the clatter of nearby explosions. What was a dull summer morning became a scene of chaos. Soldiers rushed for cover or dove to the ground. After about a dozen booms, it was over. An acrid smoke billowed over the courtyard and shards of glass were strewn all around. “Is everyone alive?” shouted a soldier. A Ukrainian soldier runs for cover inside a forward base as Russian missiles hit. Credit…David Guttenfelder for The New York Times All the soldiers in the courtyard escaped unharmed. But the Russian rocket attack killed seven civilians and wounded six others in the neighborhood near the troop base, authorities later said.