To echo justrico, pins closer to or at 3 3/8 for symmetrical balls will flare the most and try to Rev up the fastest. Shorter pin to PAP will reduced flare but place the core in a position to use energy in the front part of the lane. On asyms, it will tend to Rev up in the mids and without bigger angles, will create a smoother overall shape.
The layout chosen for the No Mercy is more of a midlane layout so you won't see a huge amount of down lane motion. The 505C2 is more of a down lane motion with a longer pin to pap and weaker cover which makes the ball bleed energy slower giving you the backend hook.
If I'm not mistaken, doesn't the No Mercy have HART core which could only be drilled one way? This was developed because of the USBC rule that didn't go into effect.