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  7  1  1  1  1  1  1  1  1  1  1  1  1  1  1  7  1  1
 0  7  0  0  0  7  7 28  0 21  7 42 14 42  0 28  7 42  7 28 28 35 28  7 14 21 42 42  7 14  7 35  0  7 28 28 35  7 35 28 35 28 28 35 21  7  0  0
 0  0  7  0  0 35 28 35  7 28 35 35  7  7  7 21 42 21 21 35  0 28  0  7  7 14 42 14 35 35  0 28 28  0 35 21  0 28 42  0 14 42 35 35  7  7 14  0
 0  0  0  7  0 35 21 21 35 35  7 42  0 14 42 21  7 21 21  7  7  0  7 14 35 42 28 28 28  0 35 28  7 28 14  7 28 35 35 35 28  0  0  7 21  0 28  0
 0  0  0  0  7 35 42  7 42  7  7  0 14  7  7 42 28  0 28 14 21 35 42 35  7 21 42  7 42 28 35 42 35 14 21  0  0 28 21 35  0 14 21  0  7 28 35  0

generates a code of length 48 over Z49 who´s minimum homogenous weight is 252.

Homogenous weight enumerator: w(x)=1x^0+312x^252+1032x^259+1560x^266+1740x^273+2058x^276+2046x^280+24696x^283+2262x^287+74088x^290+2364x^294+2346x^301+1800x^308+942x^315+306x^322+90x^329+6x^336

The gray image is a code over GF(7) with n=336, k=6 and d=252.
This code was found by Heurico 1.16 in 10.3 seconds.