what ive been told to do, and found more comfortable and more practical to snapshoot, is not to have a drop forward, or an angled bottomline (i have a screw in). it stops you having to wrap your arm round your bottle therefore reducing your profile.
i think with the bottle on your shoulder, you havent really got control of your gun properly, and you have a large profile etc.
if you look through magazines and pics, nearly all the pros have their guns set up this way, with the bottle coming straight out behind from under the grip.
do what feels more comfortable, but ive been told by people more experienced to have the gun bottle into your shoulder, and your arm coming up after the bottle, so you dont have to wrap round it.