I had a very good letter displayed but lost it when getting this site for you :http://155.217.58.58/rtddltextv.html
You will want to go to field manuls then go to FM 23-10.
Go to the apendex A.
Spring field is a very large suplier of scopes to the military, could be that the primary sniper utilizes one of these scopes.
How ever with the new .50cal. sniper weapons being fased in at specialty points of branches of services, Scopes are a very up to date subject at this point of FASING IN.
I utilize a leupold M-1 3.5-10x40mm illuminated mil. retical curently, how ever i will be fasing it out soon to the 7mm, utilization of the spring field will be brought in to replace it.
Try the site, every thing is ok as long as you stay a way from the locked pubs.
No you do not need to log in eather, just go to the library, click on the FM's and go to 23-10 sniper training were you will find what you are looking for in the apendex A.
Good Luck, there are a lot of veribels.