[Kwarde]

Indeed

pawn Код:

GivePlayerWeapon(playerid, WEAPON_ID, AMMO);

Here is a list of all the weapon ID's: http://weedarr.wikidot.com/gunlist
So you can se that a SniperRifle is 34, and not 25 25 is a shotgun (I think, wait..)
Yes, a shotgun
For example, give a player a sniper with 500 ammo:

pawn Код:

GivePlayerWeapon(playerid, 34, 500);

[EDIT]
Lol Seven posted while I was making this reply.
But whatever, @Seven: It should be a good idea to tell too that Id 25 ain't a sniper rifle