I never saw the sense in looking for something if you don't have to....rattlers or not.
Cripes doesn't everyone see the value in killing something fast?
I, also, am a firm believer in drt. There is not much meat on the front shoulders of a deer/antelope anyway and it is well worth not having to trail them.
I killed a deer just yesterday doing some depredation work. I shot her on the point of the shoulder and angled back through the lungs, exiting behind the shoulder on the other side. I only lost one shoulder in the end and it was well worth it to not have to track her into the swamp.