Tantrums and hitting

My LB is absolutely wild at the moment and I guess I'm just looking for some reassurance that this is normal? He has been hitting, pulling hair and throwing anything within reach when he doesn't get his own way. I tell him no firmly and move him away from me when he hits and move his toys out of reach when he throws them and reiterate why it's not good to do that. But when I tell him no he has a bit of a smirk on his face and it's almost like he thinks it's a game or is just doing it for attention? The tantrums have been off the scale this week and it's becoming really frustrating and difficult to deal with. He goes from 0-100 as well when he can't do something and just has a meltdown. I'm assuming it's fairly normal for this age and will ease off over time, but I don't know when to worry if there is something more going on with his behaviour. He has hit all his milestones and his speech is really good so I am not necessarily worried about his development. It's just his temperament that concerns me sometimes