The minute books or journals of proceedings of the Board of Ordnance prior to 1810 exist in several broken series.

The proceedings were usually initiated by correspondence and the Reference Books (WO 45), which give the date of the Board's minute upon any letter, will serve to some extent as indexes to the minute books where no other means of reference to them exists. The following are in this series:

• Journals of Proceedings or Board's Minute Books, 1644 to 1727 (with occasional gaps) and 2 August to 3 December 1781, containing orders from the master, Parliamentary committees and other authorities to the Lieutenant and Principal Officers.
• Minutes (Surveyor General), 1749 to 1792, recording the activities of Surveyor-General's Office in executing the Board's decisions. Containing in-letters, minutes and resulting orders.
• Board's Minute Books, 1809 to 1855, including actual proceedings of the Board providing the details on the Board decisions and resulting action or out-letters.
• Extracts of Minutes, Series I, 1782 to 1816, containing proceedings of the Board on each day it met, giving the substance of in-letters and orders, the Board's decision and the substance of the out-letters arising.
• Extracts of Minutes, Series II, 1786 to 1856, including annual indexes from 1810 onwards.
• Pension Minutes, 1808 to 1834, including applications and petitions for pensions, with the Board's decision and aswer briefly noted on them. These letters should not be confused whit those from pensioners in WO 44.
• Extracts from Minutes relating to bounty and pensions, 1818 to 1821.
• Copies of minutes relating to Ireland, 1826-1831.