If you shoot an M1 Garand you may find this site of interest:
http://www.90thidpg.us/Reference/Manuals/index.html
Scroll down and you will find four versions of FM 23-5, from 1940 to 1965, for the M1.
The early versions also have an excellent rifle marksmanship section.
There are lots of other goodies there also.
Have fun.
Douglas