Why not just sell it and buy an ACR? You could definitely get one for ~$2k and have some money left over to do some "tricking out". Not nay-saying ya here at all, just not sure you will find many people willing to trade a "tricked out" ACR for a "non-tricked out" HK Mr556A1 when the two rifles are both "relatively" similarly priced. Just trying to manage expectation here boss, from what I've seen through the years on the forum. Again, not nay-saying or trying to be a jerk here.