Not going to call it bad,
But it does need some improvements.
You do seem to know the basics of animating, but the thing is, you need to really speed up the animation, and have the characters actually do something, and not stand there and let the person shoot them and keep changing mags, (unless their dummies or something which I don't know) and that the recoil has to do something to the character shooting, not just make him stand in the same position over and over again, atleast move him back a little when he shoots and it'll look alright. It's pretty stiff, and you may want to fix that too. Also a few notes, when he shoots, he doesn't seem to know how to aim, which is lol, and when he threw the gun on the ground, it was WAY too tweened there, last thing, when he hit the last person with the pipe, it toke him like a second to actually fall, which was a little odd.
Again, it's not bad, but I can't give more than a 4 for just a very 15.5 second animation, even though it is somewhat nicely animated. Just fix the stiffness, make them do soemthing, fix the recoil, and it'll be alright. :)