There is no practical difference. They both have exactly the same magazine cuts. If anything the BDL may be a bit more stable as the bottom metal connects the front and rear actions screws with the alloy floorplate. The wood on the bottom of the mag cut in an ADL is precriously thin. In fact I've many ADL's that had cracked stocks caused by the bottom tip of the follower spring getting beneath the front edge of the magazine box. When the action screws are tightened the bottom of the stock pops out.. To get a stronger action one would need an action WITHOUT the cut for the magazine. I understand some of these were made for the 40-X series of target rifles..but have no first hand knowledge. Either the ADL or the BDL is quite strong enough..
