According to my only reference material, the 1795 Springfield loosley followed the French Pattern "Charleville" & usually had a barrel length of 44 1/2" with a .69" (nominal) bore, variations of 1/2" or so in length were the rule, rather than the exception.
Harper's Ferry, which began making muskets in 1801 made a few of the 'pattern' muskets to help, however at that time, only the Harper's Ferry Muskets were of decent quality.
The later muskets, models 1975, 1812, 1816, 1822, and 1840, all flintlocks also followed the same general design with minor differences in barrel length and close adherence to desired specifications.