Here we have a Aero precision M4 carbine lower( also refer to as the AR 15 lower receiver) the upper is chambered in 5.45 x 39 which is the same caliber as the AK 74 This comes with 2 x 30 rd mags and 100 rds. The AR 15 lower is a very adaptable lower by changing the upper you can fire about 100 different calibers, to name just a few not so common rounds here are a few examples 5.7 x 27 this would come with a 50 rd top loading magazine, a 410 shot gun it would have to have a different magazine, it can also come with a very popular 7.62 x39 ( AK 47 round). This is just to name a few of the less know rounds you can adapt this lower to shoot. In most states you can get the different caliber upper shipped direct to your home check with your state rules.
