The generator matrix

 1  0  1  1  1  1  1  1  1  1  1  1  1  1  1  X  1  1  1  1  1  1  1 3X  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1 2X  1  1 6X  1  1  1  1  1  1  1  1
 0  1 5X+1  3 5X+2  6 5X+4  5  X 4X+1 X+3 4X+2 X+6 4X+4 X+5  1 3X 6X+1 3X+3 6X+2 3X+6 6X+4 3X+5  1 2X 2X+1  3 5X+2 2X+6 2X+4 2X+5 X+3 4X+2 2X+3 2X+2 6X 3X+1 6X+6 3X+4 6X+5 4X X+1 4X+6 6X+3 3X+2 X+4 4X+5 5X  1 5X+6  4 4X+3 X+2 5X+5 5X+3  2  0  1 5X+1  6  1  X 4X+1 X+6 3X 6X+1 3X+3 6X+2 3X+6

generates a code of length 69 over Z7[X]/(X^2) who´s minimum homogenous weight is 410.

Homogenous weight enumerator: w(x)=1x^0+630x^410+210x^412+30x^413+588x^414+840x^417+84x^419+12x^434+6x^448

The gray image is a linear code over GF(7) with n=483, k=4 and d=410.
This code was found by Heurico 1.16 in 6.26 seconds.