My 450 Bushmaster upper is for sale. It has been shot some - my guess 500 rounds or so but no exact count. I bought it new and it is the 16" model.
I did add Hoot's weight to the bolt carrier group - a lead piece JB welded in place and liked the difference. See here for details. viewtopic.php?f=2&t=799
Earlier today I managed to scratch it on it's last trip to the range when the case zipper let go and the barrel slid though. The muzzle brake hit my tile floor leaving a mark on end and 1" scratch underneath on flash suppressor.
Upper shoots great - have shot clover leafs at 100 with factory ammo.
$675 Shipped - 16" upper and factory 5 round magazine. Will get pics taken later today.
Will give option of dies and brass to purchaser.
Ryan