The defense of Tobruk had been made possible by the frequent usage of the 25pdr guns. They had customarily fired some 40 tons of 25pdr high explosive rounds per day. The situation had become critical by 6 June 1941, when the guns were limited to ten rounds per day. In June, they were reduced to some five tons in all of Tobruk per day.
In contrast, the enemy artillery became much more active. They also had the advantage of having gun fire spotted from the air. The German aviators knew that there were no British Hurricane fighters as possible problems. The enemy artillery was being used to target the British artillery. The British gunners thought that if they had more ammunition, the enemy would be much more constrained in their fire. One bright spot for the Tobruk defenders was that there was an ample supply of Italian 149mm howitzer ammunition. The British artillery was organized into three sectors. All made use of the Italian howitzers.
During the first few days in July, there was an unexplained growth in enemy shelling. They were firing some 2,500 shells per day on the 3rd and 4th of July. After that, the situation returned to what had been the normal artillery fire. The British were able to match the enemy, tit-for-tat. The 60pdr guns still had problems with ammunition supply, but the 2/12th Field Regiment was able to make good use of their captured artillery. In fact, their troops in the Salient were required to fire one hundred rounds per day. The situation helped when Colonel Goodwin had translated range tables from Italian to English.
One positive development in June was the creation of an effective counter-battery organization. Lt-Col. Klein arrived to lead the counter-battery organization. He was the counter-battery officer for the I Australian Corps. By later in June, the 60 pounders were able to conduct effective counter-battery work.
A peculiar feature of Tobruk was that both sides employed raised observation posts. The enemy forces often installed tripods to hold observation posts. British and Australian posts could be on posts or they might be on scaffolding. The defenders were puzzled by ten enemy posts that were installed on 26 June, but were not used for observation posts.
Late in June, the decision-makers in London and the Middle East reconsidered the situation at Tobruk. Did they want to continue to hold Tobruk? The answer was "yes", but with a reduced garrison without "extra" troops. This is based on the account in Vol.III of the Australian Official History.