Mittlerer 17cm Minenwerfer Weapon normally employed by German Pioneer German Medium and Heavy Mortars during WW1
Weight: 525 kg
Weight of shell: 54,5 kg
Range of fire: 768 m (a/A) or 1160 m (n/A)
USMC 120mm Mortar. Artillery: Perfecting The 120mm Mortar
Weight: 818 kg
Range of fire:
.....8.2 km. Normal shell
.....17 km. Rocket assisted shell.
Weight of shell: ?? (supposedly half of 155mm shell which weighs 44 kg)
20 meter accuracy. These are guided shells.
Not a perfect comparison as I am not aware of a WWI era 120mm mortar. However I think a WWI era pioneer would be astounded at the advance in mortar technology.