sonrider 657:
I have several of the Cavalry Arms lowers that I have not been able to build yet, but my goal was to have something as close to an m1 carbine in concept but in a 5.56 format. I understand Brownells may have the remaining stock of lowers if anyone is interested in a Cav AR 15 buildup. I bought mine for around $110 each.
The Cav Arms lower is about a pound lighter than going with a separate receiver and buttstock.
My suggestion to your question on getting the weight down a little more would be to buy a 14.5" barrel (CMMG is one source) with a permanently attached (welded) flashhider to bring it past the 16" requirement. I don't have a 14.5" barrel, so I haven't weighed it against a thin 16" barrel to see what, if any, the weight savings might be. The CMMG profile looks like a M4 shape which should be heavier than the thin 16" barrel you have. There is someone out there who will re-profile the barrel for you but that obviously adds to the cost. Also, you have to consider the lower velocity you get from a 14.5" barrel versus a 16" barrel.
I wish someone made a 14.5 inch thin barrel - with a chrome lining.
If you don't mind revealing your source, where were you able to obtain the carbon bushmaster upper? I didn't see it on their website the last time I checked, but I may have overlooked it.
Great looking rifle - I personally wouldn't change anything as it is about as light as you are going to get.
