Our 10rd Stainless Steel Magazines will fit any AR-15 or M16 rifle with an upper half chambered in the 5.56 mm or .223 caliber.
Material: Stainless Steel
Q: Can I use any other caliber of ammunition in this magazine?
A: Using ammunition other than what is specified may cause malfunctions and feeding problems.
Absolutely love it, perfect as it is works and feels the same as aluminum but more sturdy and durable, the only thing I would probably will file the follower a little in front so when it has ten rounds it's not that much of resistance wile loading, overall tested all of them working like it should, you definitely have to hit the magazine if you have 10 rd to sit properly. Well done Stag Arms!!!