The generator matrix

 1  0  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  0  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1  1
 0  1  1  a a^6*X+a^2 a^3 a^6*X+a^4 a^5 a^6*X+a^6  a a^6*X+a^2  0 a^6*X+1 a^5 a^6*X+a^4 a^6*X+a^6 a^3  1 a^6*X+1 a^5 a^3  a X+a a^6*X+a^2 X+a^5 a^6*X+a^4 a^2*X+a^5 a^6*X+1 a^5*X+a^4 a^5*X+a^4 a^5*X+a^2 a^3*X+a^2 a^2*X+a^2 a^3*X+a^5 a^3*X+a^4  0 X+a^2 X+a^3  X
 0  0 a^6*X  0  X  X a^3*X  X a^2*X a^3*X a^6*X a^2*X a^2*X  0  0 a^2*X a^6*X  X  X a*X a^3*X a^6*X a^4*X a^3*X  0 a^5*X a^6*X a^4*X a*X a^6*X  0 a^3*X  0  X a^5*X a^5*X a^2*X a^3*X a^6*X
 0  0  0  X a^6*X a^5*X a^3*X a^2*X a^5*X a^6*X a^6*X a^4*X a*X a^2*X a^5*X  0 a^4*X a^5*X a*X a^3*X  0 a^3*X a^4*X  X a*X a^5*X  0 a^3*X a^2*X  X  0 a^4*X a^2*X a^4*X a^3*X a*X a^4*X  X a^2*X

generates a code of length 39 over F8[X]/(X^2) who´s minimum homogenous weight is 248.

Homogenous weight enumerator: w(x)=1x^0+259x^248+840x^253+2184x^255+2695x^256+896x^259+8232x^261+6888x^263+4410x^264+12544x^267+38360x^269+22680x^271+12705x^272+43904x^275+67256x^277+25592x^279+11592x^280+518x^288+322x^296+217x^304+49x^312

The gray image is a linear code over GF(8) with n=312, k=6 and d=248.
This code was found by Heurico 1.16 in 8.45 seconds.