I wish to trade a NEW unfired Bushmaster 14.5 AK flatop A3 upper(16inch legal) for a NEW unfired bushmaster A3 20inch preban upper OR Bushmaster A3 16inch M4 preban upper. Trade would be even up, I would prefer the M4. Trade (yours and mine) would be Less bolt and charge handle. Ak upper lists a few dollars MORE so if this is what you want, the trade is a deal. Thanks.