Yeah, I have to call bogus on that as well.
It's possible, but difficult, to see a handgun bullet in flight, depending on lighting conditions.
Like most hunting snakes, rattlers detect heat and odor better than they can see.
But, here's where it really falls apart for me...
The bullet is traveling 900 feet per second.
If someone is taking a handgun to a rattlesnake, they're probably going to be very close, my guess is within 20 feet or so.
If we say 20 feet, that bullet is going to (if I'm doing the math correctly) cover that distance in 0.0222(repeating) seconds, or about 1/45th of a second.
In that time, the rattler would not only have to pick up the bullet's flight, but would have to react quickly enough to strike at it.
A rattler can accelerate its head from 0 to 60 mph in about a half a second...
I don't think that is nearly quick enough for everything to work out.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.