Several elephants and brown bears have been killed (cleanly) with traditional gear, some with bows as low as 75# (I think that's what Fred Bear used?), without extreme FOC, without a "super" bow, without high performance strings, etc. For the sake of the argument, say the average draw weight for elephants with a traditional bow is 90#.
Pretty sure than an elephant would require at least 3 times the penetration of a whitetail. Super thick and tough hide, tougher and thicker muscle and bone to penetrate before getting to the lungs. Once you get past a certain point (I think around 60-65#, depending on the bow) you get to a point of diminishing return...i.e., going from 60# to 90# won't up your performance nearly as much as going from 30# to 60#. Then take away the high performance string (most were shooting ropes for strings). Take away the super high FOC. Take away the "modern" recurve design (some were killed with longbows). Do the math, it's not the least bit far-fetched to understand how a whitetail can be killed quickly and cleanly with a 30# pull. Off the top of my head, if a whitetail required 45#, I'd say it would take a minimum 150# to 200# draw weight to kill an elephant. 'Course we know that's not the case.
I was talking with Dr. Ashby on the phone a few years ago, and the topic of water buffalo came up. He was certain that my
[email protected] longbow would do the job just fine. You can dang-near throw an arrow through a whitetail, as long as you hit the right spot. Hit the wrong spot, it won't matter if you are pulling 100#. Draw weight doesn't compensate for poor arrow placement (I know...there are exceptions, I'm talking about the rule).
Also just remembered a local young lady (who I think is also a distant relation). A season or two ago she killed a nice whitetail with her NASP bow (Genesis). Looks like a compound, designed to shoot like a 35# recurve (when turned all the way up). Not sure if her bow was maxed out or not, I know she has a shorter draw length, but she killed the deer quickly and cleanly.
There are plenty of examples of deer being killed ethically and legally with lighter draw weights. There are also plenty of examples of misses and wounds with heavy bows by people who didn't put the arrow in the right place. No doubt this was, at least in some cases, because they were over-bowed. What's comfortable in the back yard after warming up can be a devil getting the string back on when you have been sitting still for a while, in the cold (or not), then all of a sudden your heart is in your throat. Been there, done that.
Just my perspective. Lightest draw weight I have personally hunted with in the last several years is 52# at my draw, but if I were to have to drop down to 30#, it wouldn't keep me from hunting because I know if I do my part, 30# will get the job done.
Chad