These are great AR style carbines that take Glock mags, The 9mm & 40 S&W are interchangeable just barrel & bolt, the 45 ACP is priority due to mag size, I like these better than the JR carbines and they are accurate and easily taken down for cleaning or caliber changes. TNW Aero Precision survival rifles, left is 45ACP & right 9mm both wearing Bushnell Holosights, , (original Eotech's) and used for up to 100 yard 3 gun competitions so pistol & Rifle use same mags, I did add 8" rail sections to the short rail they come with, easy to add free float or clamp on types for accessories.