» Wed Mar 30, 2011 7:32 am
Bring up your Pip-Boy, and check your hot key. Which ever is hot keyed as a picture of two bullets (Should be the one on top) is the key you need to press to change your current ammo type. If, for some reason, you can't do that - then go to the; "Items < Ammo" section of your Pip-Boy, where you should be able to toggle which ammo types you'd like to use (Granted you have extra ammo types for your current weapon), using the action key.
Edit: A bit late. Lol.