I'd call him a 3.5 year old from what I see. Some pics the head looks like a mature buck, but the body never looks close IMO.
In pic #2, he is bigger in the back in than the front end like a doe instead of a mature buck.
There was a 2.5 year old shot on my farm that went 130" and all he was was mass on a 12" spread....those pop can base bucks have to start somewhere.
I am going to say this buck is mature and a definite shooter! Plenty of mass there...