Initially the armoured cars also had a machine gun placed in the turret for anti aircraft use but were proven to be ineffective and were removed in the '30's. Tracking a fast moving aeroplane with a turret mounted machine gun in a ball mount proved practically impossible to be of any use.
Tests of the prototype revealed, that despite the advantages of the car such as a relatively strong armament, sufficient armour and a rear drivers position making reverse driving easier it was found that the car actually had low speed and manoeuvrability. Usage of a truck chassis was pretty standard in this era making construction and maintenance easier. One of the results of using a truck chassis however was a lack of all wheel drive, resulting in a poor off road profile. Despite having quite a large silhouette there wasn't actually much room internally. Both weapons and arrangement quickly became obsolete.
Because of these facts only 10 of these vehicles were eventually ordered with the whole series being completed by 1931
On 1st September at the outbreak of the war, two armoured car troops were assigned to the outposts of the Mazowiecka Brygada on the defensive front line on the Prussian borderlands. At the opening of hostilities the 2nd troop was firing upon advancing German troops from ambush positions. In the evening they laid an ambush near Krzynowloga Mala village destroying all three armoured cars of a reconnaissance unit of the 12th Infantry Division. Two of the Ursus' were damaged with Warrant Officer Wojcieszak suffering a head injury although he continued to serve.