There seems to be a fault with this gun's design. We got one delivered and it lasted for about five minutes before developing a weird fault where it would just spit out each dart that was loaded into it. It made no difference whether it was cocked, and happened without pulling the trigger. Literally, we put in a dart and it just popped out without any umph. So we sent that one back and got a replacement.
The replacement arrived yesterday morning nad has survived nearly two days of play before developing the same fault, although this time round it's intermitent and can be overcome with perseverence, for a time at least.
It is probably worth mentioning that we have also had a Nerf N-Strike Elite Strongarm Blaster
for a couple of weeks and it has proven to be very durable so this fault seems specific to the Firestrike.
So, the Firestrike was fun while it lasted, but just lacked the durability that you'd expect from a toy like this.