What do you think? This is a sledgehammer that I repurposed today. Started out as an 8lb sledge now it's a 5lb cross peen.

 

         

Well for me, that size would be for use with a striker, and I'd want a long handle on it.

Nothing wrong with that!  I regularly use a 4lb sledge because it moves metal fast and easy, even when doing light work, and have often thought of turning the one end into a cross-peen.

I'm new to smithing but so far I like the feel of a heavy hammer.