He's between 1360.8 and 2268 grams. (I know it's a large margin, but its hard for me to weigh him without getting bit right now.) The mice I've been feeding him are roughly 20 grams a piece (so 60 grams total)
You just did your own math. Even at your lowest eyeball estimate 60 g is not anywhere close to 10% of body weight. If you're right, you would need to double that.