"How Many Shots Can I Get From a CO2 Cartridge" is yet another super common question I get on a daily basis which seems simple enough yet has a rather long winded answer…
The reason I can not give a simple answer is because there are many factors involved that determine how many shots you can expect to get not only from different guns but also on different days in different shooting situations.
I can tell you that one 12 gram CO2 cartridge can deliver as few as 30 shots to as many as 200 shots from an airgun. Let’s talk about why there is such a variation in how many shots you can expect from a 12 gram CO2 canister?
Here are some factors that will determine how much CO2 is used up while shooting a CO2 Airgun.
Temperature can greatly effect how many shots you will get from a CO2 canister, the reason for this is because CO2 requires heat to expand, if more heat is available then less CO2 is required from the CO2 canister with each shot. In very cold temperatures especially when the gun and CO2 canister are both very cold, a CO2 gun may not even function as the canister and gun can freeze up. Because of this temperature effect you will not only get more power in warm temperatures but also more shots from a CO2 cartridge. And likewise in cold temperatures you will get less powerful shots and less of them per CO2 tank.
CO2 Canister Size:
Since CO2 cools as it is used up, the CO2 tank will also become cold as you shoot and as discussed already a cold CO2 tank is less efficient. Smaller CO2 tanks will cool down much faster than larger CO2 tanks so when shooting rapped fire with a 12 gram CO2 cartridge you may only expect to get about 20-30 good shots before taking a break and letting your gun and the CO2 tank warm up again. Some CO2 airguns use 88-90 gram CO2 tanks which allow for a lot more rapid fire shots before having to allow for warmup time. Even a dual 12 gram CO2 airgun will operate better when shooting rapped fire than a single 12 gram CO2 airgun since it has double the CO2 capacity.
CO2 Valve Settings:
On pretty much all CO2 airguns there is a valve setup that when the hammer is dropped the valve is opened for a very short period of time allowing the CO2 to escape from the CO2 cartridge and enter the breach and barrel area of the gun propelling the BB, Pellet or Airsoft round. How long this valve is open for will determine how much power the gun will have and also how much CO2 is used up for each shot. More CO2 released by the valve equals more power and less shots per CO2 cartridge, less CO2 released by the valve equals less power and more shots per CO2 cartridge.
Another hot topic is Blowback operation, some people love it and some people hate it. Blowback operation simulates the slide action found in semi auto pistols and provides some recoil and also allows for the hammer to be cocked between shots which allows for true single action operation just like a real semi auto pistol. So what’s not to love about blowback operation? Well blowback operation steals a little bit of CO2 every shot to make the slide operate back and forth. This robbing of CO2 means you will get less shots from a blowback gun then if it where not a blowback gun. Because of this robbing of CO2, blowback guns are often less powerful, since the CO2 being released from the valve has to propel the ammunition and work the slide blowback operation.
Semi and Full Auto:
When shooting a CO2 airgun, you may be tempted to shoot fast and furiously! I know it’s fun, but as mentioned earlier shooting quickly will cool the airgun and the CO2 canister down leading to poor performance if you do not allow the airgun to warm up between shots. For this reason full auto airguns tend to be very ineffective when it comes to CO2 efficiency, especially when using a single smaller 12 gram CO2 canister. For instance the KWC Mini UZI can shoot in both semi auto and full auto and only uses a single 12 gram CO2 cartridge. When shooting in semi auto you can expect to get two 25 round magazine of shots as long as you allow the gun to warm up a bit between magazine reloads. When shooting in full auto with the KWC Mini UZI you will get about one magazine worth of shots with very noticeable cool down at the end and then will have to pretty much switch over to semi auto to get perhaps only another half magazine worth of shots to finish off the CO2 cartridge. Still worth the fun shooting in full auto in my books :)
Even when shooting in semi auto mode, you can shoot quickly or take your time and be more precise. The more time you take in-between shots, the more shots you will get from your CO2 tank and the more power each shot will have. So if you want to get the most out of your CO2 cartridge, then avoid the temptation to blast everything in sight as quickly as possible. Or give into it and simple stock up on CO2!