The national law is 18 for a long gun, 21 for a handgun. State laws always apply, but I've never heard of any other age for purchasing firearms. Some states restrict the sale of specific types and models, but as far as I know, that has more to do with "assault weapons" than with handguns. Check government websites and ask the store owners.
Also, if you're interested in getting a carry permit, I would wait till youre commissioned, change your state of residence to TN, FL, or TX (no income tax) and then get your permit issued from one of those states. They all have reciprocity agreements that work all across the south. I don't know how the IL permit compares, but I'm sure it'd be more strict.
That also brings up another interesting thing I've noticed. When you go to buy ammo when under 21, the clerk is not supposed to sell you rounds for handguns, however if you tell the theyre for a rifle, they have to sell it to you (22 rifles, .45 carbines, etc). Just interesting how the law works.
Also, if you're interested in getting a carry permit, I would wait till youre commissioned, change your state of residence to TN, FL, or TX (no income tax) and then get your permit issued from one of those states. They all have reciprocity agreements that work all across the south. I don't know how the IL permit compares, but I'm sure it'd be more strict.
That also brings up another interesting thing I've noticed. When you go to buy ammo when under 21, the clerk is not supposed to sell you rounds for handguns, however if you tell the theyre for a rifle, they have to sell it to you (22 rifles, .45 carbines, etc). Just interesting how the law works.