Quoted:
Yes, vehicles. Jeeps, pickup trucks, etc. Equipment: missile guidance systems, radar control boxes, etc. NOT TANKS, NOT APCs, NOT IFVs.
These common mis-statements do a disservice to us all.
-David
Edgewood, NM
One Caveat to that, it all depends on the armor package of the vehicle. An M113 (which is an APC) is considered a thin skinned vehicle, it's armor will only defeat 7.62mm rounds, and the M113A adds a spall liner, so you'll still get penetration from .50BMG depending on range and the round used.
Tanks are a definite no go for .50's you may get some optics (if you know the system) but the armor's to think, and besides they never hunt alone.
IFV's again, you may get the optics but the modern up armor packages have sufficently hardened them from all but cannon rounds or tank main gun rounds.
Just to reiterate what David said, the .50BMG in the military role (assuming its not an M2) was designed for anti-material missions, i.e. engaging light vehicles, missles, people, equipment etc..
You can engage light APC's, BUT if you do IMHO your out of your mind, unless its a last ditch effort, if you know anything about armor, they don't hunt alone, and you may get a round or two off, but at the end of the day, there in an armored and armed pillbox, and you've got nothing but your ACU's to protect you.