Sight pins distancing

[Nostradamus]

I have a 5 pin Axcel sight on my compound bow, and the distance between sight pins is different and does not not seem linear.
20-30yrd = 2mm
30-40yrd = 6mm
40-50yrd = 6mm
50-60yrd = 5mm
Gap between first two pins is minute, and increases dramatically; then the gap between the last two pins is smaller.
I sighted the pins by shooting at least 20 arrows at each distance. I know the arrows are heavier (FMJ).
So, the bow shoots flatter at close distance - seems reasonable, but why such a great rise at other distances, and then smaller toward the end?

Any thoughts/experiences would be great. Thanks.

Mathews Halon 32, DW=70lbs, DL=27.5"; FMJ 28" arrows.

(Sidenote, when I had the bow dialed in at DW=65lbs, the distance between the pins was incremental and made sense).

 

[Ucsdryder]

Yeah that’s not right. In my experience when someone is seeing pin gaps like that it’s usually because of your peep. Usually you’re coming out of the bottom of the peep. You can try a nose button or something to make sure you’re getting a consistent anchor. Make sure you’re peep is the right size to frame your scope housing as well.

 

[Nostradamus]

You make a very important point about the peep/anchor location. In my single-track mind to get arrows in tighter groups, I may have completely overlooked the aspect of positioning the pin through center of the peep, and then onto the target. I will work on that and check my pin-gapping tomorrow. Hope to get some update here tomorrow.
THANKS!!!!!

 

[Rob5589]

I agree, probably alignment. I recently tied on a "nose button" and it really helped with my peep alignment. I found that I would change my anchor ever so slightly when using the lower pins. My pins are more linear in spacing now.

 

[N2TRKYS]

I’ve never used my sight housing to line up my peep sight and still don’t. Heck, I didn’t even know that was a thing until reading it on the internet a few years ago. Lol

 

[*zap*]

I set the pins where I want them as far as spread and then shoot to see the distances. 22, 31, 42 as an example.

 

[Johnboy]

Yeah that’s not right. In my experience when someone is seeing pin gaps like that it’s usually because of your peep. Usually you’re coming out of the bottom of the peep. You can try a nose button or something to make sure you’re getting a consistent anchor. Make sure you’re peep is the right size to frame your scope housing as well.

I've been battling this same issue, and I think @Ucsdryder nailed the source of the problem.

 

[jmez]

Heavy arrows you see a lot of drop at 30 compared to 40. Mine looks the same way. A measured 1mm difference on the last pin is you not the sight/bow.

 

[rileybassman]

I’ve never used my sight housing to line up my peep sight and still don’t. Heck, I didn’t even know that was a thing until reading it on the internet a few years ago. Lol

I'm the same way... For like 15 years I've always centered the pin to the peep... Not sure I could or even want to change... I have a big nose... It's a good anchor point lol.

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[Nostradamus]

Thanks Ucsdryder, I shot some more at 50 & 60 yards and re-worked my sight pins by doing my best to align the sight pin in center of the peep. The pin spacing seems to be improved much, there there is definitely a big drop from 30 to 40 yrd pins (pic included). Great discussion here, thanks all for your suggestions and experiences.

 

[Rob5589]

Still kind of odd. My bow speed is about 260 and does not have that large of a gap from 30-40. But, if you're dialed in, that's just what it is.

 

[MattB]

Ponder the trajectory that would chart and then compare that to the force of gravity. It doesnt work that way. You are doing something very odd from an alignment perspective.

 

[Whiskey_Fish]

Thanks Ucsdryder, I shot some more at 50 & 60 yards and re-worked my sight pins by doing my best to align the sight pin in center of the peep. The pin spacing seems to be improved much, there there is definitely a big drop from 30 to 40 yrd pins (pic included). Great discussion here, thanks all for your suggestions and experiences.
View attachment 210437

You said center the pin in the peep... do you mean center the housing in the peep? The peep to housing alignment should be the same always and then the pins fall where they may. If you center on the pin you have a different anchor for every pin.

That’s why a previous poster mentioned your housing diameter.


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[Nostradamus]

You said center the pin in the peep... do you mean center the housing in the peep? The peep to housing alignment should be the same always and then the pins fall where they may. If you center on the pin you have a different anchor for every pin.

That’s why a previous poster mentioned your housing diameter.


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Unfortunately that may be my next thing to check my bow. So far I’ve been putting the pin in center of the peep. The peep diameter matches the sights-housing perfectly, so I’ll try that as my next option.
But I’m not sure about that at this time, as my bear hunt is coming up in 2 weeks!!

 

[87TT]

The housing should center in the peep. It should be centered when you draw your bow with your eyes closed and anchor before opening. That's why the put that bright colored ring on the sight housing and have different size peeps, dove tails etc.

 

[5MilesBack]

Here's my sight for 20-80, very linear. I always draw and anchor the same so that my peep completely surrounds my sight guard perfectly. My 50 yard pin is always dead center in the middle and I raise or lower for whatever distance I'm shooting.

 

[theleo91386]

You could very well have a form or tuning issue going on. If your arrow porpoises as it goes down range you can get funky pin gaps. Same if you tend to drop your bow hand to soon after the shot or use to much pressure with the heel of your hand. You can get away with centering the pin in your peep, you just need to be very consistent with your anchor points and form. If it were impossible to get accuracy this way and a rigid set housing was mandatory, single pins and sliders would be impossible to use.

 

[Nostradamus]

5MilesBack, that spacing is quite impressive, what kind of bow/poundage do you have, and is that a metal string running through the center of the housing?

theleo91386, still working on my form every day , however the bow is paper tuned the last time I shot and checked at a bow shop.

Thanks for suggesting a kisser/anchor point for the nose - is there any particular way to position the nose anchor? Or do I just draw at 20yrds and mark where my nose touches the string - and attach that anchor there? - hopefully that anchor works for all the pins thereafter.

 

[Rob5589]

I tied on a small rubber band, drew the bow, referenced my nose position, move rubber band as needed, repeat until set. Then I removed it and used serving to tie ot on permanently. When setting it up, make sure your head is up and arrow level to the ground. You want perfect position for the tie in. I bet once set up, you'll be moving those pins into a more linear spacing.

 

[Johnboy]

Unless you have a weird fluttering issue with your arrow flight (which would change the deceleration of your arrow), it will travel in a basic parabolic trajectory in accordance with laws of physics and stuff. Therefore, if your pins don't have a logical spacing that agrees with this principle, something about your technique is the cause.

I like the suggestion above by @Rob5589. And I also agree with the observation about the colored ring on your aperture by @87TT. Constant anchor technique and consistent concentricity between your peep and aperture should be just the ticket. Try these things out and see if your pins begin to make more sense.