Question about bow poundage and arrow performance.

[BowEd]

Loon...With 20 yard shots the force of momentum by a 650 or 700 grain arrow for penetration is a bit farther than a 500 grain arrow.Even though it may be going slower.It gets pretty technical that's for sure.The calculator shows it.Just some really good food for thought and understanding.The analogy was explained like this.Throw a plastic wiffle ball then throw a baseball.Which one's gonna leave the bigger mark?Kind of extreme but I think as the speed ramps up the difference gets greater with arrow shafts.Seeing impact with a slow motion camera I'm sure would reveal that the extreme FOC shaft being lighter weight in the back 2/3rd's of the shaft would'nt experience the reverse paradox that a center balanced shaft would experience.That energy on the FOC shaft would go or stay forward for better penetration.These shafts have to fly as good without feathers as with also of course.Accuracy is pretty much a given with all of this.
willie.....My friend Gary had to go to very lightweight carbides to get his 32% FOC on his shafts.350 grains on the tip on a 636 grain arrow.Which Dr. Ashby found to be close to the overall weight that did the best.It can be done with wooden ones too,but not quite as high a percentage.Personally if I was to get after it I would use spruce first thought off hand.Stiff and light weight.Foot it[purple heart or hedge] with a heavy tip and taper it to the nock.Gary said all he did to minor adjust elevation flight was twist his string a time or two to move his string nock.That is'nt much.There's all kinds of BS sales pitches out there.Biggest one is this rage chisel tip butterfly broadhead.Junk!!!I'm very glad to read that with all the testing Dr. Ashby did he found the 2 blade broad head to be the best for penetration.Makes sense.
Brad....My other friend Grant has told me more than once his son killed his first deer with a 35# bow.Don't know if that was legal in Iowa you know but I know the guy and he does'nt lie.So just to kill a deer does'nt take a whole lot if in the right spot.With your elk hunting now going on that's a different story.I sure hope you can get within range of one.These two guys I mentioned have both shot elk out west and many times lately just can't get closer than 50 yards to them.Your first encounter was a biggie I'd say.The other fella with us on 3D shoots Ed has shot 13 elk out west.All with a long bow.
All this info is just out there you know.It's interesting to me.All of the info that Dr. Ashby found over years and years of testing he did with his own money,and did'nt take a dime from the company that approached him.These tuffhead people.He's a phycisist himself.Talk about passing it on heh....lol.

[bradsmith2010]

thanks Ed, I have lots of" theories"  certain set ups are proven over and over, so I put alot of weight on what has worked,, and try to keep an open mind for improvement,, I am lucky to have  "Tested" some set ups in real hunting situations, and seen others first hand using the long bow in successful and not so successful applications,, most under estimate the effeciencly of heavy arrow and two blade,, you just have to see it work to really get it,, it can become complicated on paper,,,
I made an arrow for a friend for a buffalo hunt,, it weighed about 1000 grains,,,,,2 blade broad head, the bow was osage, b 50 string, average,, probably shooting a 500 grain arrow 165 fps,, not sure what the 1000 grain was doing,,
his shot was about 30 yards, off horse back, the arrow came out the other side,, some would say 165 fps with 500 is very slow,, and it might be compared to some bows,, but in a hunting situation, the end results are really telling,, in this situation the broad head and the weight of the arrow got the most out of the cast of the bow,, later he told me the arrow hit a bit lower than he was aiming,, I guess so ,,that hunt was filmed,, the arrow was in perfect conditon ,, just a little blood on it,,

[Lumberman]

Wow that's wild to blow through a buffalo.. Really enjoyed reading some of Ashby's papers. It is good to know some of the actual reasons why/how the FOC is important. May affect the way I make some of my arrows these next few weeks

[BowEd]

Yea you guys it's just food for thought you know.Understanding things.Im in no way close to an engineer or physicist but do respect their findings.More so than promotional sales pitches from companies.Actual usage like you said tells it to ya.That means more shooting and bow making and more arrow making....lol.A good bow for hunting is important but equally and even more so the way the arrow is set up too.Target shooting too.Where it all begins for testing.

[BowEd]

After further looking at Dr. Ashbys' info and videos he's proven by demonstrations the eyes can see that an arrow even 20% heavier will fly farther with at least 32% FOC.Because of the lessened paradox the extreme FOC shaft experiences recovering quicker from leaving the bow.Problem lies in that to get that percentage of FOC in natural material wood shafts is pretty hard to do in primitive archery.Carbides allow it to be done a lot easier.I can get it with shoot shafts with a heavy tip into the 20%'s FOC balanced but that's about it.Still noticeable though.Normal balanced shafts are around 10% at best.I'd have to try my idea of bare shaft tuned spruce shafts footed with heavy tips and with 2" feathers.Because of the extra weight up front the spine needs to be increased to handle that.All this will get a normal shooting bow to be more lethal and a more efficient bow to be more lethal yet.All of this one may say does not conform to primitive archery.Not so.The tribes in New Guinea figured this out with their bows and arrows.Through trial and error I imagine.

[willie]

an arrow even 20% heavier will fly farther with at least 32% FOC.Because of the lessened paradox the extreme FOC shaft experiences recovering quicker from leaving the bow

interesting, could you supply a link to where those observations about arrow flight were made?

I must have got sidetracked in my recent Ashby reading. Did see quite a bit about FOC relating to penetration though, but that's a different subject.

[BowEd]

Yes.It's on the same tuffhead site.I'll get back here in abit to tell ya.

[BowEd]

Go to tuffhead site.On the left hand side click on Ashby May 2013 Dallas Texas.Go to video number 4.

[willie]

Ed
checked out that video, and I wish that we could see the flight of the arrows better in the flight test where he is making that claim.

He can demonstrate more range with heavier arrows because the extra weight and extreme FOC adjusts the dynamic spine of his straw to his bow. His demonstration is comparing apples and oranges because the lighter straw is grossly overspined and just shoots terrible.

ashbys claims for better penetration with more FOC seem more well founded to me, as bradsmith has demonstrated.

[BowEd]

Yes the heavier straws' spine may have been softened to fly straighter.While the lighter straws spine made it shoot at more of an angle.I see your point.Maybe somewhere he does shoot real arrows to prove his point.The jury is still out in my book about this yet.