The Firearm Blog reports that the Colt's submission to USMC's IAR program is now sold as upper only. It's supposedly $2000.
http://www.thefirearmblog.com/blog/2016/12/14/original-colt-iar-contract-evaluation-uppers-sale/
Link to the company: http://www.usarmamentcorp.com/parts/part-page/282
From: The Firearm Blog
