A load belongs to a mission
Enterprise’s squadron reports record different loads within the morning dive-bomber formation on 4 June. VB-6’s striking aircraft each carried a 1,000-pound bomb. VS-6’s aircraft and the air-group commander carried a 500-pound bomb plus two 100-pound bombs apiece. The figures describe the weapons’ weight classes, not the amount of explosive filling. M17
The later 5 June strike used a different recorded load: one 500-pound bomb per aircraft in the mixed formation. A profile that assigned every Dauntless its maximum advertised payload would erase these operational differences. M17
The inspected entries do not by themselves settle every bomb mark, explosive filling or fuze. Those details require the relevant ordnance returns and technical manuals.
Hiryū’s bombs
The Japanese first-counterattack table records eighteen dive bombers and expenditure of twelve No.25 ordinary bombs and six No.25 land bombs. Those are separate weapon categories in the original record. The table demonstrates a mixed expenditure; it is not a complete inventory of the carrier’s magazines. M41
The selected working reading preserves those labels rather than giving every bomb an unsupported modern description. Detailed fuze and penetration comparisons remain to be checked against technical records.
Hiryū’s torpedoes
The second-counterattack table identifies Type 91 modification 3 torpedoes. Nine were recorded as expended by a force containing nine Hiryū attack aircraft and one from Akagi. A note says the Akagi aircraft did not release its torpedo. That is a direct example of why aircraft launched and weapons launched cannot simply be equated. M41
The exact modification matters. Specifications and release limits from a later Type 91 cannot safely be applied to this June 1942 entry merely because the family name is the same.
Release, hit and effect
The attacker’s expenditure record tells us what was reported released. The defender’s damage record answers a different question. Yorktown’s technical report describes bomb damage to the flight deck and boiler uptakes, followed by port-side aerial-torpedo damage, flooding and loss of power. M18
Neither record is a perfect measurement of the other. A reported release is not proof of a hit; a hit does not always cause the damage expected; disabling a ship is not the same as sinking her. These distinctions explain why the battle narrative compares both sides’ records.
Follow Hiryū Fights Back or compare the British weapon changes in Torpedoes from the air. The Mark 13 and Type 91 profiles examine the technical evidence, keeping later improvements separate from the weapons available in June 1942. Individual American malfunction counts and exact bomb marks remain unresolved.