Those how prefer using CO2 with sniper rifles can check these CO2 Magazines from Shooter especially designed for  the Ares AMP-DSR1, M200 Intervention, and the PGM Mini-Hecate available at RedWolf Airsoft. This will provide more power and range to these sniper rifles and will allow you to play in colder temperatures. But you will need to readjust the power of your rifles to meet legal limits in your own countries.

Shooter CO2 Magazine for ARES M200 Cheytac Intervention

Shooter CO2 Magazine for ARES PGM Mini-Hecate

Shooter CO2 Magazine for ARES DSR-1