Not knowing all your bow data etc, I just ran a typical hunting setup through "The Archery Program" and here is what I found.

29 Draw: Medium Cam: 7" brace: 70 pounds: 445 grain arrow produced roughly 248 f/s. The same setup with the 470 grain arrow produced around 256 f/s.

Now in the pin gap.....
out to amost 50 yards it is less than .05" different! This was a 30" sight length (peep to pin) had it been shorter the pin gap would have been even less.

The reason that this is the case is because the heavier arrow although slower, will maintain more speed down range because it is just plain heavier, and air will have less effect on it.

Have fun........a very slight adjustment .05" or less is in order for shots over 50 yards.

Happy Shooting!