As far as I've heard, you cannot take a private weapon into a war zone. Partially because of Geneva Conventions, but also due to supply line issues. What good is a pistol that you cannot resupply? Grandma sending you ammo thru the mail doesn't count, because it's illegal.
If you are stateside, buy what you want, if you are deploying, accept what they give you and good luck..... God Bless you for serving your Country.
Zhur