Is there any chance he’ll get bigger

I always wanted a king snake and chanced upon one on fb marketplace the cage he was in looked fine and I got a really good deal anyway he’s about 27 inches in length and an inch and a half by his widest point I didn’t ask the age just assumed it was maybe a year old when I got home I messaged the guy how old the snake is ,he told me he had the snake for 2 years and he’s probaly around 4 then went on a rant about how he had a major head trauma injury and asked if I wanted to buy more stuff and a whole bunch of yap the next day I offered the snake a fuzzy mouse and the snake gobbled it up immediately now I’m confused cuz it seems he should be bigger but what do I know