Point weights

[Devon_Archer]

most of us have seen or had experience of shooting or watching arrows that seem to be heading for the 3D or gold and suddenly dipping and going low

when an arrow suddenly loses height at a distance, i.e. not flying in what we would call a natural curve, it isn't usually just a matter of tip or arrow weight

it is more likely a matter of arrow balance, this does show up more with very light carbon arrows and heavyish points where the point of balance is very far forward

the arrow is still moving at the same decreasing rate of speed as it leaves the bow, as it has received the same amount of forward energy from the bow,

but an unbalanced arrow flies well until it reaches a certain point then the weight of the point takes over the balance and points the arrow literally into the ground, and that is the direction it follows, it dives into the ground at the same speed that was taking it forward

it does not and cannot suddenly lose energy or momentum, unless acted on by an outside force, such as wind or rain

arrows do not stall in the same way as an aircraft wing

the same arrow weight balanced differently can fly much further and flatter

this is really born out by the fact that since carbons came to be the norm, actual scores haven't increased huge amounts since the days of alluminiums being the norm, allies with their heavier shaft weight are in most cases balanced further back along the shaft and can fly better and less twitchy

going for the lightest carbon shafts, really does need lighter points than ally to maintain the flight balance

unfortunatly as arrow selection charts are just a starting point for selecting arrows these days, many of us buy the wrong arrows and changing them, tuning them, and setting them up to fly as we want them is an expensive and time consuming activity not many of us can afford

[easy]

Originally Posted by King Custard

are you sure you need 620's at your draw length?- is that why you've loaded them with 120gn points? 670's should be your arrow I reckon with 100 gn points

120gr points were recommended to me to try first off, as i am likely to get better groups at distance....apparently.

I haven't had a chance to try shooting at 80 or 100 yards this week, i've put 100gr points into six shafts so i'll test them at the weekend to see if i can tune them, then see how they get on at distance.

Cheers for he comments. Weird how you hear a few people say one thing and it becomes a trend, i've heard of quite a few archers trying 120gr points recently, but i wonder how many will still be using them come May.

[Des]

Originally Posted by easy

Cheers for he comments. Weird how you hear a few people say one thing and it becomes a trend, i've heard of quite a few archers trying 120gr points recently, but i wonder how many will still be using them come May.

Hands up to that.

I've been trying heavier points as i've gone for shafts that are on the stiff side. But i'm sticking with 100gr now. I found that just going up 1lb helped to sort the tuning out.

[King Custard]

Originally Posted by easy

120gr points were recommended to me to try first off, as i am likely to get better groups at distance....apparently.

I haven't had a chance to try shooting at 80 or 100 yards this week, i've put 100gr points into six shafts so i'll test them at the weekend to see if i can tune them, then see how they get on at distance.

Cheers for the comments. Weird how you hear a few people say one thing and it becomes a trend, i've heard of quite a few archers trying 120gr points recently, but i wonder how many will still be using them come May.

good call! These 'over heavy' points are great - at heavy poundages, yes they supposedly/should make arrows group better in the wind....but as you've sussed already Im sure- at 'normal' poundages like ours, heavy arrows have to be shot higher into the air...a longer, higher arc...hence more time in the air and likely more time spent in faster winds!- completely negating any plus points!
Come May, June, July, August with generally 'stiller' air 120gn points are a total waste of the power in a sub40lb bow.

[ASW1973]

plus 100 grain points are designed to be matched up with 4XX and stiffer arrows.
Some compound shooter CAN use 120 grain points in lighter spined arrows with good results but then they are not suffering the slow speeds of recurves.

Des:
very glad that you have seen the only way to effectively tune the bow is through bow weight, not point weight.

[archer_thom]

That makes sense, I see you've been giving this some thought.

[Devon_Archer]

I see that almost all arrows are still sold by the draw weight of the bow / draw length

this is fine as a starting point, as everything has to start somewhere, but these so called ideal lists are really so inaccurate they are no more than a hint

let us take wood arrows to start with, but the same effects are accross the whole range of arrows

you can buy wonderfully straight spined arrow shafts in a set of for example 30 - 35 pound @ 28 inch

is that for a longbow ? AFB ? Hunting Tackle with quality limbs or cheap second hand shot out limbs ?

no concern point weight, fletchings, nocks nor for speed of the limbs, speed of string etc etc

the same is true for carbons and allies, let us take 2 bows, both recurves, one is a basic woody handled training bow, the other the latest Hoyt 6,000,000 or whatever number they are up to this week

both bows have 35 pounds on the fingers, both of them have fastflight, both of them shot by the same archer so same draw weight and length

on the charts, exactly the same arrow specified !

will they all shoot the same arrow as well ? not a cat in hells chance

I remember some years ago a high up in a certain arrow manufacturer was proposing that they provide a standardised weight and spined arrow, and a chrono, all linked to a new set of arrow selection charts,

you simply shot their standard arrow over the chrono with your bow, to get a reading from the chart that gave a much better starting point for spine and weight

Not perfect but a hell of a lot better starting point

it was binned before it was launched as the certain arrow manufacturer reckoned it would lower sales of arrows by up to 30% as archers wouldn't have to swap and change arrows and components so much

So we all tinker and play with our setups, swap bits and pieces, buy yet another set of shafts of a different spine and yet more points, nocks strings limbs bows and so on

fun isn't it ?

[JohnK]

I remember some years ago a high up in a certain arrow manufacturer was proposing that they provide a standardised weight and spined arrow, and a chrono, all linked to a new set of arrow selection charts,

And now an arrow manufacturer does. It's the Easton Bow Force Mapper and has been around since 2005. I'm not sure about using a standard arrow, but it does calculate weight, maps draw force curves and recommends arrow spines. According to a shop owner I know who has it, more often than not it recommends what the charts say anyway.

[EVC]

Originally Posted by King Custard

good call! These 'over heavy' points are great - at heavy poundages, yes they supposedly/should make arrows group better in the wind....but as you've sussed already Im sure- at 'normal' poundages like ours, heavy arrows have to be shot higher into the air...a longer, higher arc...hence more time in the air and likely more time spent in faster winds!- completely negating any plus points!
Come May, June, July, August with generally 'stiller' air 120gn points are a total waste of the power in a sub40lb bow.

This subject does interest me. I am shooting McKinney II's at 29.5" (nock grove to shaft end) with 110gns points and FlexFletch vanes. I was longing for as a high FOC as possible as I have heard some strongly believe it makes the arrows behave better under wind.

Currently my arrows' FOC is near 15% and I was planning to use kurly vanes in a new set I just bought to increase it even more. The MK II shafts are more than 25gns lighter than the ACEs that I think would suit my setup (520). I suppose this fact could mitigate (at least in part) that speed loss mentioned above. However, based on what I have read in this thread I wonder if I should take more 10gns off the points and switch to kurlys so that the FOC stay around 14% and the arrows weight drop 16 or 17 gns.

Any comments/hints?


Elder

[Devon_Archer]

JohnK

Is the software the one where you put in the draw weight and arrow length then it does the calculation, or is this where you give the arrow speed as well ?

If it is the arrow length / draw weight software, yes I have seen this and it is basically a database of the charts and a quick lookup table

If it is based on all the bow speed and variables of power and speed as per chrono info then I haven't seen that one and would love to see it