Pro hunting shows and expanding broad heads...

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Originally Posted by J

I agree with what you are saying, but not your math.

Since F=MA, or KE = MV^2, you get a bigger drop in KE from velocity drop (and assuming similar deceleration, your force) than you do a drop in momentum where p = mv. Simple number examples follow.

KE = 100 * 8 = 6,400, KE = 100 * 6 = 3,600 a ~44% drop in KE.
Whereas p = 100 * 8 = 800, or p = 100 * 6 = 600 a 25% drop in momentum.

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Good but the actual KE=.5(m)(v)^2. But the KE equation does nothing. Both arrow will be (or should be ) flying with the same mass and velocity. Meaning they will have the same KE. The reason theye lose a fraction of speed is opening the blade. Which will effect its momentum which isnt primary based on Velocity. And having change in momentum based on time duration and force needed applied to opening the blades. The change in momentum is still tiny as it takes such a small force to open them over what a millisecond?

I gotta say that my Grim Reaper expanded very well and blew through my antelope at 47 yards this year. The antelope didn't go very far and never did find my arrow [Mad]

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Originally Posted by runninlope

Good but the actual KE=.5(m)(v)^2. But the KE equation does nothing. Both arrow will be (or should be ) flying with the same mass and velocity. Meaning they will have the same KE. The reason theye lose a fraction of speed is opening the blade. Which will effect its momentum which isnt primary based on Velocity. And having change in momentum based on time duration and force needed applied to opening the blades. The change in momentum is still tiny as it takes such a small force to open them over what a millisecond?

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The energy needed to open the blades is signifigant and is easily seen by the lack of exit holes on game, especially if the arrow hits a flat bone like the shoulder. I'll see if I can get Tim Gilliangham to send me some info from tests he did for Gold Tip.

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Originally Posted by runninlope

Good but the actual KE=.5(m)(v)^2.

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Yeah, you are right. Been too many years since engineering school. DiffEQ and convolutions are still with me, the laws of motion are just barely holding on in the back of my brain.

Actual KE is not as much as a factor as how quickly that energy is lost.

I have a great idea.. Someone let me hunt their land and I will shoot a deer,elk,antelope.. Whatever with my mechanical spitfire.. Then you can shoot one with your fix blade and we can see who had more fun... These threads are stupid and yeah they always draw me in because I love spitfires and some of you like your fix blades... I like that there is some archery to talk about on here but how about pictures instead?

My work here is complete. [Poke] [Coffee]

Haha

This was my first year hunting archery, and I went with the G5 Strikers. I tried three other broad-heads including one mechanical, and I have to be honest the Striker flew exactly like field points. Even when there were some cross winds the Kentucky windage I held off was about the same. I could hit a 3" circle on my target every time with them from 50 - 60 yards. At that point mechanicals lost all advantage for me and listening to some of the horror stories that I have heard I just went with the striker. Now if I can just get a shot on an elk I would be pretty happy.

All discussion about KE and passthroughs aside, I think the major reason some people like mechanicals is due to the way they fly. Especially in the wind. That being said, I don't ever use mechanicals.

IMO there is a big difference with how all of the fixed blade broad heads that I've personally used in the past, travel through a crosswind compared to field points. Of course, the effect is less noticeable the faster your bow is and the shorter the range. Additionally, my personal opinion is that FOBs work but I use a whisker biscuit on my hunting bow which means I stick with Blazers.