Prior to the purchase of the Henry rifles, the 7th Illinois seems to have had many Harpers Ferry 1816 altered 69 caliber muskets that may have come from Illinois stock piles at Springfield IL and the 20,000 plus removed from the St Louis MO Arsenal prior to the major hostilities. These were moved to Springfield, Il and used to arm the earliest regiments. In "Arming the Suckers, by Ken Baumann, the Seventh is listed as having 804 Altered 1816 Harpers Fery Muskets. After Shiloh in a report by Major Richard Rowlett of the Seventh, he states that there is a shortage of 69 caliber ball required fro his muskets. OR I, Vol. 10 Part I p. 163. Apparently the 1816 altereds were still in use then. A number of .577 Enfields were aquired and US Rifled Muskets 1855- 1863 were being acquired when possible.
By the end of August to early September 1864, the Seventh was finally armed with the purchased Henry repeaters.
If my GGGrandfather Walter J Mallett mentioned by Mike Elliott in an earlier post on this topic would have had the good luck to have had a Henry in September 1863, he might not have been captured outside Corinth MS and he may not have spent the remainder of the war in various prisons such as Andersonville, Bell Isle and Florence stockage