Okay, stripped down to the basics, its the same action between ADL or BDL.
You start off with long action, or short action, which is caliber dependent.
Then you go to ADL or BDL. The BDL has the hinged floorplate, the ADL has no floor plate (blind magazine). The ADL magazine is slightly different also, there is a tiny screw that holds the magazine well to the action on the ADL's, the BDL's do not have this, as the floorplate holds the magazine in place.
The triggers, bolts, and action itself, are the same.
There is a 3rd action size called "small" which is a short action setup for the .223 and small case head cartridges.
Finally, the bolt face size is important, because you need the right size based on the cartridge you want to shoot. There are 3 "main" case diameters. Magnum, .30-06, and small (these are the semi-common names for them). The Magnum is the .30-06, 7mm's, and other magnum type cartridges (including the new short magnums). The .30-06 is the most common and includes the -06 (obviously), .308, .270, .243, etc etc etc. The small is the .223's, 222's, .17 Rems, etc. When action hunting, be sure you know the caliber you want your future project to be in so you get the right bolt face diameter, or else you are up the creek. The new short magnums are a pain because they are a short action (means shorter bolt) with a magnum case head diameter. This combination was not manufactured until the new short mags, so finding a used action to work with is not easy.
MEL
