At 250 lbs and 30%BF ur LBM is around 175 Lbs

175 x 15 = 2625 cals

That is around ur mtnce cals, i would shoot for around that number to begin with and gradually drop the total calories

At 30% BF you can kind of crash diet a little bit IMO

Do not worrie abou Loosing LBM.

Focus on doing lots of weight lifting and cardio up to 7 days a week for around 30 mins per day