The Galaxy G31(D) is a new cheap Barrett that is a welcome change in this class of rifles. It's almost all plastic (the only metal part being the barrel), really lightweight and easily manouverable. It shoots 120 m/s out of the box, and uses internals that of an A&K SVD (or so I inspected). The co2 conversion for that gun should fit in here.
The humongous beast only weights that of a MP5, just 3 kilos. You can actually use this Barrett effectively in a skirmish, it's just as easy to carry around than, let's say, a VSR-10. The barrell goes off by taking one screw off and then twisting counter clockwise and pulling. You beed to do this to adjust the hop up. I set the hop for 0,28 gram bb's, and it shoots surprisingly far and is pretty accurate.
The magazine is huge but only takes in 25 bb's. There's an empty space for reserve bb stash or co2 capsules in case you need them. The manual also points this out.
Even though the gun is plasticky and light, it's sturdy and won't squek or wobble one inch. The cocking lever ain't stiff and hard to pull like that of an spring SVD, it's really easy to use.
Just over a 100 bucks this is a steal. A truly epic spring rifle by Galaxy, bravo!