Yea, I was gonna say there is no way for a snake that is 3+ feet to get full off of 3 mice week when the this species of snake can eat other full grow snakes.

If you stretch out a full grown or maybe a juvenile rattlesnake (these are what i read most cal kings eat) and line up mice next to it from head to toe you will need at least 3 - 4 mice to complete the whole body of the rattle snake.

So basically if i am thinking this the right way one rattlesnake can easily equal the length of 3 - 4 mice lined up behind one another.

Also usually when it comes to snakes and moving them up to bigger prey for regular snakes (meaning ones that dont eat other snakes) feeding 3 mice per feeding usually means your snake can swallow a (assuming yall feed pre killed, frozen etc) small rat or two.

So There is no way 3 mice can be over feeding because snakes when they arent hungry they wont force their self to eat...

Snakes can get obese but this just means that some owners are feeding prey at a size not needed for the snake...or maybe too often