If you find that mission hard, you'll cry blood when you start looking for the mission pages from it
About the manuals, there has been some controversy about it and there are two camps.
One side believes that it works as they did in Brigade E5, they'll increase the speed in which you gain skill in said weapons when carried in the inventory. Sniper skill when using SVD, heavy weapon skill when using grenade launchers and so forth.
The other side, the one I belong to, thinks that they make no difference. In Brigade E5 you could only gain 5 points every week in those skills, in 7.62 you can gain 5 points every day. This would mean that you theoretically can have a 100 point in 20 days and that would seriously f-up the balance of the game and the devs decided to remove that function.
But if anyone feel like trying it out, I would be glad to be proved wrong in my assumptions
