Colt 1878 d.a

[mtmarfield]

   Greetings!

   Judge: Try Dixie Gun Works; I believe that's where I found replacement grips for my 1902.

                M.T.Marfield

[Colt Fanning]

Howdy,
I have an 1878 in 44-40 that I got cheep and tuned up so that it shoots fine in single action.  I shoot it in NCOWS matches.  In double action
it moves the hammer back only about 3/4 of the distance for single action and this is not enough fall to fire the primer.
What does one do to cause the hammer to release later in a DA?
Regards
Colt