Every time a writer uses the phrase "point blank range" to mean "extremely close range", God clubs a baby seal to death with a physics book. Just because most of the English-speaking media uses the phrase incorrectly does not imply that you must, too.
In ballistics, it is the distance at which a projectile will hit the ground if you perfectly level a gun and fire it, which can be over 300 yards for high powered rifles. That's three football fields, which is obviously the opposite of "extremely close range". And if it's a handgun and its PBR is only three feet, then your gun sucks, because the PBR on even the most piece-of-crap squirt guns is about 2 yards.
If you must use the phrase and the victim is indeed at very close range, use the qualifier "within". Within point blank range is perfectly acceptable, because the victim's range falls inside the range of PBR, but by saying "at point blank range" implies the victim was shot at the gun's maximum PBR.
Think of the goddamned baby seals next time, won't you?