FQ, he ALREADY has the 12 Ga. (for which ammo is a little easier to find) and he already has one pistol cal carbine so he can go ahead and have the fun and bragging rights of the AR build, but if it isn't 100% he can fall back on the other carbine.
Also there is reduced recoil ammo option for the 12 ga.
Tom, he was talking about one for the GF. I didn't presume that she had gun borrowing priviledges. (Southern gentleman and all that

). Seriousley, Marlin used to make a 9mm and .44 mag carbine a while back, and ruger made a supersized 10/22 in .44 mag that was supposed to have a pretty mellow recoil. I've not shot either, just throwing them out there. I love other people asking "what gun should I buy" questions as it lets us live vicariously. Let's see, $1,000 in my pocket and what shall I do with it......?
FQ13