the production model, Me-323D, could carry 21,495-lb (9750-kg) cargo load over 621 miles (1000 km), or 120 troops with full equipment, or 60 stretcher patients with medics
Not sure about the speed, as these are the ones for the E-2, which had increased armament and armour
speed: 149mph at 4,920 ft
service ceiling 14,760 ft
armament:
1 20mm mg 151 in each of 2 turrets (one on each wing)
2 0.51-in (13mm) mg 131 in nose doors
5 more mg 131s firing from beam positions and rear of the flight deck