Without doping some "lookin" I can't say with any degree of accuracy, but I remember reading a thread, I believe was on the old Misissippi board, that stated the Univ. of Miss. Grays had over a one mile distance of attack at Gettysburg. That is the reason they never made it to the Union lines to add any degree of pressure.

In H. Grady Howells "to Live and Die In Dixie" page 381 "---all the Confederate artillery was left with Lee so there would be no softening up"

The only mention of distance I can find is page 382 "at 800 yards they (Union) opened a terrifick fire of shot, shell, grape and cannisterand when the trooops got within 400 yards the musketery united with the cannon and it appeard to come from millions."

GP