For home defense a Colt 6920 was my pick. I pulled the 16" barrel and put a Colt factory 14.5" in it's place.
I would avoid BCM like they carried the plague.
Why avoid BCM?
From personal experience. They don't stand behind what they sell. Years ago I listened to all the BCM fan boys on another site and bought one of their SPR uppers. The damn thing consistently shot 4" groups at 100yds. I called, nobody answers. The recording says they are too busy to talk to people on the phone and to leave a message and they would get back to me when it's convenient for THEM. I do this 4 times over the coarse of a week and NEVER get a return phone call. After that I figure maybe it's best to email. I had done this before and knew they had no trouble returning emails when I wanted TO BUY SOMETHING. 6 emails later and I hear nothing but crickets.
In the emails I explained my problems with the upper. I told them about trying many different load combo's using my reloads and factory ammo in many different bullet weights and powder combo's to give it a fair chance of finding something it liked. I told them I had run over 400 rounds down the barrel to make sure it was broke in before I contacted them.
A few more emails to BCM later, I finally get a response that went something like this:
Sorry to hear that, we suggest you keep shooting it and maybe it'll get better. Most of our customers report MOA accuracy with that upper. $1300 for a "precision" upper with AK-47 accuracy and no support other than encouraging words. No thanks.
This has been probably 5-6 years ago and maybe things have changed but I wouldn't chance it.
