Aileron Displacement
Been a long time since flying a Boeing, but I’m thinking the amount of actual aileron displacement with a given control wheel movement is dependent upon flap setting. What I’m saying is, you don’t get full aileron displacement with full control wheel movement until you’ve selected Flaps 40. At Flaps 0, moving the control wheel to the stop gives little actual aileron displacement.
As I recall.....and I could very well be wrong...this is the case on both the 727 and 737. (I have no experience on the newer 737s.)