First off, make sure to checkout my Table Top Review for the Umarex Beretta CX4 Storm for all the specifications and details on it.
In this Filed Test Review of the Beretta CX4 Storm .177 caliber pellet shooting air rifle I shoot 5 rounds through the Chronograph to get a real world average FPS of this detuned Canadian version. As expected the Beretta CX4 Storm does not get anywhere close the 600 FPS the non-regulated version claims to get and even with fairly light 6.9 grain pellets I got an average of just under 400 FPS, perhaps a little too aggressive with the Canadian regulating of the CO2. I would have liked to have seen much better Feet Per Second performance from the pellet shooting Umarex CX4 Storm.
On the other hand this CX4 replica air rifle was incredibly reliable when it came to operation, I did not have even one misfire or failure to load a round even with the rather unusual 30 round belt-fed magazine, which one might think would be prone to problems. The Umarex Beretta CX4 Storm has a very snappy feel with its blowback operation that gives you a confident feeling when shooting and the 8 pound trigger seems to actually lighten up the faster you shot it :)
During my Accuracy Test using a magnified scope from 30 feet out in a semi-rested position, I got pretty decent results but nothing amazing, just over a one inch 12 round grouping. Again this airgun is made for fun and you can really empty the 30 round magazine fast and with good precision. I would not recommend it for any type of small pest control because it is a bit underpowered but for target practice and plinking it works very well.
As far as recommending this gun, I think it is very well made and it performs excellent, if you can get your hands on the higher FPS version then it would be a nice upgrade to the one I was testing. The price may be a tad high but it really is a very good quality air rifle overall.
My YouTube Video Table Top Review of the Umarex Beretta CX4 Storm Pellet Rifle: