There are a few differences, other than the aforementioned rear sights, between the M64 and M67. The M67 comes with serrated tangs versus the smooth tangs of the M64. The M67 was available with a red plastic insert in the front ramp sight versus the plain blade of most M64's. Most M67's, being Combat Masterpieces, come with an adjustable trigger stop that improves the feel of the action.