We gate way to few ammo as sniper, we strugle to find the best position to be stealth and we need to get out because we run out of ammo extremly fast.
The only way to increase bullets for your snipers, is through ammo pouches, or unlock through the blue tech tree an engineer. Those last can build ammo boxes
you can ask your bots for some ammo via ALT button (it’s 5 bullets per ask).
or yeah, you can indeed ask ammo through bots 
That’s the starter position. Later a player may purchase small and large ammo pouches and other sniper rifles which allows the players to bring 80 rounds with him/her.
Yeah, ammo pouches can be equipped after unlocking backpack slots on snipers and engineers can be unlocked for sniper squads to build ammo crates, 3 snipers, an engineer and an assault guy with an SMG is my recon composition and it definitely helps.