TFOX

Exactly Jerry,spine is probably the single biggest obstacle with getting the 2 to group together.With so many trying to get as heavy as possible and ending up with overspined arrows it does make it very hard to get the 2 together.In those cases they are much better off just grouping the broadheads.Overspine as well as underspine arrows want to kick when center shot is right.The easiest way to fix it is to move the rest and that causes the 2 to impact different.If spine is not correct then the arrows need to be coming off the rest as straight as possible and imo this causes way too many problems.Not coming off the rest straight but the fact you have to move center shot to achieve it.

Fletchead

I do group tune there Rack. I think I explained that. Maybe not. If I didnt, I figured it was just common knowledge. Forget about bare shafting Rack ? Thats probably why most people have problems getting both to group together. They look at the chart, buy an arrow off the shelf that fits there fancy, and then try to tune the arrow to the bow. They get good holes, which can be acheived with near perfect form at ten ft, and horribly over or underspined arrows. Paper doesnt prove squat. Its a starting point. Then they wonder why the two never hit the same.You gotta tune the bow to the arrow. All I can tell you is when Im done they snuggle right up with f.pts when Im done group tuning bhds. I end up refletching when Im group tuning bhds.because I enjoy seeing those bad boys group tight. Is this the right way. Dont know, but it works for me and those ole bhds. just keep going where Im aiming if I do my part correctly and the deer keep dropping. Two inch groups with f.pts out to fifty on my good days, and the occassional robin hood,which I feel is as good as Im capable. I see no reason to switch. Middle of the road tuning my a$$. Maybe a true guru could tune it even better, and shave another quarter inch off the a.m.o.a, but I dont feel my shooting abilty would know the difference. Im mentally as good as Ill get.You come up with a better way that gives me even more fletch cutting accuracy and Im all ears. Rack I am not trying to argue. I just disagree. As Len stated earlier, thats whats so great about archery. There are many ways to acheive the same end.

Tfox, good point, but exactly how do you acheive the exact same f.o.c. Different arrow length for hunting and target? Id like to see some f.p.s. comparisins on the two heads, and find out just how much speed is shed. Maybe one of these days Ill get bored and try and destroy my chrony. Another thing Ive seen with some good target shooters who have a hard time getting the two to group together, is theve set their bows up for a high left tear which supposedly stabilizes better. It dont work with bhds.

Rack-attack

If you go through all the hard work and sweat to group tune your broadheads, and get 2" groups at 50 yds - why in the world would you mess with that to move them together??

I have no doupts that your setup - the way you described it until that last point, is a dead on setup

What I am saying is if you or anyone group tunes there broadheads, and achieves superb groups - (the best groups you can achieve) - who cares where the field points hit.

Why mess with a perfect broadhed tune to move the POI together. Thats when I feel a " middle of the road is achieved"

yes its nice to have them together, yes sometimes after you group tune they are dead on with fp' s and sometimes as TFOX stated they are a few inches off.

No yelling or bashing here Just a debate boys

TFOX

Fletchhead,I achieve the same foc because I believet the Easton school of thought on this.You probably feel if a point is longer,then it changes foc.I do not and neither does Easton.The reason I don' t is because that foc in relation to an arrow is being used in relation to spine deflection.A longer point doesn' t change this.Weight is the only factor that is used.HOWEVER,if you are using a really long broadhead with big blades,it may take a stiffer spine to controll the outside variables that is inflicted upon the arrow.Such as if the arrow kicks from any reason.Untuned bow,wind or even a limb or an animal.This is why I and most believe that using a SLIGHTLY and I mean SLIGHT stiff arrow is good for hunting.


Right or wrong this is the way I see it.How a simple question can turn into a major debate is incredible.I love it.[:-]

Straightarrow

I think a lot of assumptions are being made with this statement. First, if the POIs are not together, what makes anyone think the tune is " perfect" ? It may be the best you have been able to acheive, but perfect? It is my contention that it may be as good as you can get at that particular draw weight, but if you bareshafted for perfect spine, you would find those POIs in the same area.

Rack-attack

Because I and some others here believe that what a field point does has nothing to do with the tune of broadhead.

Let me define my perfect - bh and field points in the same size group or very close to same size group. I think that is what we are trying to achieve.

My group tunning methods do not ignore draw weight, tip weight, arrow size, fletching type etc. And one or all of those may be tweaked as I group tune - and they will be tweaked to what my bh is telling me.

I am all for bare shafting for spine if that is what you think is good. Proper spine is very important. I do Bareshaft to set up my FP' s - and to test my form.
But since I do not believe BH' s Must fly the same as fletched fieldpoints - I will not assume that a bareshafted fieldpoint, is better at showing me how my broadheads will fly than......well how they actually fly.I would rather check my Spine with broadheads on.

The bh' s will tell you everthing you need to know.

And you are right, Very often they will hit very close to the FP' s, and both camps here could easily end up at the same tune, but through two diff. routes.

Fletchead

Rack in answer to your question, the moving of the two different points together is how I got to the two inch groups. By the way I said my best days. My bad days are really bad. Rack, I had about three thousand words wrote out, and then checked in and saw your last response and the last sentence. Amen brother.

Fletchead

TFox, I was half asleep last night and missed the main jest of your last response. I understand the weight deal, but even with an inch and a half long broadhead, even though weight is weight havent you added length to the shaft and thus made it react slightly weaker.Ive just always got f.oc. of my f.pts, and then just figured a half a point difference. Once again If Im spined, and like you say slightly over, they hit together so never really measured again or worried about it if it still fell within guiedlines.Sattelite seems to agree, and be thinking along the same lines,because of the design of their matchpoint system. How many tenths of a point off.o.c. is it, I have no idea. Thats why so many people right on the edge get good groups with f.pts which is acheivable with a horribly spined arrow and large heli fletch and then switch to bhds. and flight and grouping open way up. Theyll group together, but no where near the f.p. groups. That extra bhd. length definately does something,spine wise. If its not f.o.c., then what is it. Drag alone wont take them low left or right to the extremes Ive seen. Im gonna dig out different weight field points and old bhds. today and find the difference. Ill probably just confuse myself more. Wait, that aint possible. Once again T, not arguing with you or Easton, just trying to make sure for myself. Something just doesnt seem to make sense.

c903

Excellent excerpt from an arrow tuning article.


" Some people say you can get broadheads and field points to hit the same place. That might be true in some cases, but more often, it is not. Look at the physics of it. A broadhead is longer than a field point. That will change the balance point of the arrow and you will have more weight forward as well as the points of arrow flex will change. Now you also have a set of wings on the front of the arrow and the fletch acting like wings on the back trying to off set the wings on the front.

Broadheads will have less affect on a heavy slower moving arrow because there is more mass and less air pressure on the broadhead blades. Arrows that are flying over 280 fps will not shoot broadheads well because of the light arrow weight needed to shoot an arrow that fast and the amount of air pressure on the broadhead.

Recently there was a big dispute in NASCAR over the rear spoiler height on one manufacture’s cars. They wanted to raise the rear spoiler by something like 1/4” because they could not keep up with the competition. Does it make sense that a broadhead will not change an arrow, but 1/4” added to the rear of a ton and a half car traveling at about the same speed as an arrow will make a difference?

Typically, people will find that their broadheads will hit low left of their field points. Some people say you should move your nocking point and rest until field point and broadheads hit the same place. That is fine if that is your main purpose [/b]instead of accuracy.[/b] It is best to tune your bow for your broadheads and then sight in for your broadheads. Do not worry about it if your broadheads and field points do not hit the same place. Mark your sight for each or have a different sight for each. Remember, accuracy is what counts.

Do not compromise your accuracy just so your arrows will hit the same place with broadheads and field points."

TFOX

Well I just checked some foc' s and it seems that the broadhead did change the balance point of about 1/8" .This was only a change of 15.8% to 15.4% foc.I was wrong with that.But this was also checking to the end of the shaft and not to the end of the point.This is where I agree with Easton.Foc affects spine mainly because of weight.Checking to the end of the point is fine and may be best,I really don' t know.It just keeps you to the safe side of spine instead of to the low side.The reason I don' t like to measure the point is simply that a point will not flex the same as the shaft.It does affect the way the shaft flexes but doesn' t flex the same.That is why I like staying to the stiff side,ever so slightly,just in case.I don' t think there is a right or wrong but just a different way of looking at the same thing.This is really getting down to the very smallest of details.[:-]