On my 2005 RK Custom, the stock 12 inch Harley shocks never scaped or bottomed out..
the ride was somewhat stiff and jarring over bumps. I installed Progressive 430's 11.5 in.
and have them adjusted to nearly full stiffnes and the crossmember on the frame scrapes when going over imperfections in road surfaces, seems like gradual humps and bumps are the main causes.
I am riding solo, 180lbs the shocks have the regular spring rate springs, anyway I don't think this should be happening... The forks are not lowered and seem to be operating fine
now I'm thinking maybe they need heavier oil? any suggestions??

 

I have the same shocks, never bottomed out even with 2 up. I think there are two adjustments rebound and stiffness.

 

What bike do you have them on? Do you have the standard or heavy duty springs?
do you have the 11 1/2" inch size?
I'm asking because something is just not right, with my setup!! I'm thinking of sending them to progressive to evaluate and maybe change to heavy duty springs, if all else is well.
I bought them used from the HD forum classifieds, they were called 11" for Street glide
from Progressives website I determined that they had to be 11 1/2" now I'm wondering about that too. When I took the stock 12" HD shocks off the 430"s looked only about 1/2 " shorter