The generator matrix

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

generates a code of length 45 over Z7[X]/(X^2) who´s minimum homogenous weight is 252.

Homogenous weight enumerator: w(x)=1x^0+432x^252+594x^259+2058x^264+348x^266+12348x^271+246x^273+264x^280+156x^287+222x^294+96x^301+36x^308+6x^315

The gray image is a linear code over GF(7) with n=315, k=5 and d=252.
This code was found by Heurico 1.16 in 45.9 seconds.