Yes it can, it's an M60 with a custom model. (Think Version 1 vs Version 2)
Are you writing the byte to the correct place? (Note the AUG doesn't work with all proficiencies I think)
To quote NH9
However I think there is a spare byte in between the values...5A 00 (ATTACHMENT) 00 (CAMO) 00 (PROFICIENCY) 00 (RETICLE)