I found this site on the M1 Garand it has some good information and the best free copy of the M1 field manual (FM 23-5).
The gentleman who ownes the site, in his own words "I worked diligently to reproduce the original type style and layout, including the cover, 26 photos (modeling the poses myself), 10 drawings and two data tables. Assembling the contents, I also took great pains to place specific paragraphs, tables and photos in their original places on the original page numbers. This is not just a photocopy like you get now from The U.S. Government Printing Office, it is a double-sided printed replica of the original manual (I was a professional technical writer for 12 years -- The USGPO would be proud of this manual!)"
My M1 Speaks for Me
(The gentleman who ownes the site, in his own words: "I've retired, so the manual PDF is now free for downloading here. I no longer offer a printed version -- take your PDF to a local copy/print shop!")
M1 field manual (FM 23-5) link
An excellent resource, and a very generous way for him to "bow out".