How about at an angle, the berm at the back far corner with the angle of fire letting a loose round to go into the deer lease. Berms do not need to be that much, as you are going to have excavating done to dig your house
have the diggers push a good sized mound to act as the back stop. Six foot high, with a good solid base makes plenty to stop bullets, provided you kept the targets lower on the berm. Make sure that the soil used to be the berm, is mostly free of rocks, you want the bullets to be just absorbed by the berm verses the chances of rock causing ricochets.
We had a road re done on our property a few years ago and when we asked the guy driving the D7 to make a berm out of the waste, he was happy as that was soil he was not having to move off the site.
I think we payed another 50 bucks for the berm and from it we got a clean flat, 150 yard range with a good 6-8 foot tall berm. We also had the driver make a pile on the side that we use as a pistol range, about 35 yards from the shooting line.