I got a package from Midway on Friday. It had a bunch of reloading stuff, along with a DPMS Lower Parts Kit, a carbine buffer and buffer spring.
Installing the LPK was interesting. The Cav-15 Lower Receiver is very tight in all tolerances. Every part fits very tightly. I lubed everything with Slipstream Lube as I installed it, and the trigger group wasn't too hard.
Some of the parts weren't used, or installed differently because it's a CAV-15 lower. The Selector detent and spring have to go in from the top, instead of with the pistol grip. That part was tough, since I had to install the spring and detent, hold them down with a punch, and try to get the selector in there. This is where that extra tight tolerance became troublesome. I got it almost lined up, then tapped it with a nylon mallet to get it in. It worked, but I smashed my thumb in the process. Pretty nasty.
I also discovered that you need a pin, which isn't included in either the LPK or with the Lower, to hold the buffer retaining pin in its hole, because there's no buffer tube to do that. I'll have to get one of those next week, since I'm on vacation this week.
The upper fits very tightly in the lower as well. I almost have everything I need to finish the upper, except the barrel. I just found out my barrel is backordered a month or two from DPMS, so that could seriously delay the build. Don't know what I'm going to do about that.