Compound Bow Problems at distance

AJ16S

Member
I picked up a second-hand Switchback on eBay a little while back and over the months have bought all the other bits I need to shoot it. Gave it it's second outing last night and decided to have a pop at the longer distances. At 80yds I have the sight (almost fully) extended so the scope just fills the peep, but I'm almost at the bottom of the adjustment. At 100yds I have the scope as low as it will go without the fletchings making contact and I have to bring it in by 9cm to get the arrows on the boss. I know it's not comparing like with like, but that's the same distance I have to bring my recurve sight in when going from 80->100 yet that's only pulling 44lbs vs the 55lbs the Switchback set at: this doesn't seem right to me.

Given that this is only the second time I've shot a compound bow this is as likely to be something I'm doing as it is a bow setup issue, or it could be that that's just the way it is with a Switchback and I need to wind it up a bit more.

Suggests/comments/observations welcome.
 

geoffretired

Supporter
Supporter
Your anchor point with the compound, could be higher, if you use a release aid. That might cause the sight marks to be low all across the ranges.
Do you use the same arrows for both? That could be another cause, if the compound arrows are heavier.
To get some sort of comparison; you could look at the sight marks for distances up to 80y and see how spread out they are on each bow.I would expect the faster bow to have sight marks closer together if the sights are on the same extension.
 

AJ16S

Member
Didn't think to take the comparison with the recurve further - good idea. The gap between sight marks for a 20yd difference is almost exactly double for the recurve, however in both cases, at 100yds, I would need to move the sight/scope about 7mm lower than I am able to without contact - so I guess it makes more sense that I would need to bring the sight in by about the same amount to get the same vertical difference.

Arrows are different, by the way. Recurve are Cartel Triple 600, Curly Vanes and 327gn; compound are Cartel Triple 400, Plastifletch vanes and 337gn.
 

backinblack

Active member
I am likewise a compound newbie and use a similar IBO rated bow to the Switchback, also set at 55lbs and my sight marks on the rail go from 1.1 for 30m to 4.4 at 100 yards fully extended (Toxonics sight) and so I have plenty to spare - arrows weigh around 385 grains. Peepsight height may be an issue - after I shortened the draw length half an inch I decided not to put my nose on the string as it was no longer comfortable and I moved the peep sight up some and from this gained around a cm on the sight rail at each distance.

Mind you, I am not using a scope but one of the Beiter pins with a level on it - no doubt that helps with clearance.
 

geoffretired

Supporter
Supporter
The bigger spaces between distance marks indicates that the recurve is slower,yes? However, if you look at the 20y marks for both bows, the height above the arrow of those marks, will indicate how the anchor points vary, bow to bow.Chances are the compound starts closer to the arrow at 20y, so it can't be lowered by as much as the recurve before it is too close to contacting the arrow. If that is the case it is not likely to be a bow problem so much as the higher anchor point with the release aid.
 

Martin Heelis

Active member
Ironman
Hi

I ran your bow and arrow specs through Archers Advantage and it buried your triple 400's in the red at the weak end of the scale. Not sure how this will affect things though.

Martin
 

AJ16S

Member
I'm not too surprised. I went for the 400s instead of 300s as my experience with Cartel Triples and X-perts is that their arrow selection chart over-spines. I assume that AA get their arrow info from the manufacturer rather than empirically testing every flavour of arrow themselves. What's the compound equivalent of bareshaft tuning so that I can find out how close they are to being right? (I have much to learn)
 

Martin Heelis

Active member
Ironman
I'm not too surprised. I went for the 400s instead of 300s as my experience with Cartel Triples and X-perts is that their arrow selection chart over-spines. I assume that AA get their arrow info from the manufacturer rather than empirically testing every flavour of arrow themselves. What's the compound equivalent of bareshaft tuning so that I can find out how close they are to being right? (I have much to learn)
Possibly a combination of walkback and paper tuning. I keep meaning to do paper tuning myself but it's not been calm enough. I'm going to end up doing it in my house this weekend I think.

Don't forget to check your sight is mounted squarely as well. The scale bit should be at the same angle as the riser. Then check that the scope is running at 90 degrees.
 

geoffretired

Supporter
Supporter
Bare shaft setting up of the bow will get the nocking point sorted out, as for recurve. If you use a release aid, the spine won't show up much as the arrows hardly flex during the power stroke.Arrows are more likely to go one side or the other, because of bow hand torque, than spine.
 

backinblack

Active member
If you go on John Dudley's website: ARTICLE and look at the article "Horizontal Impact" (and several similar ones elsewhere on the site) it sets out how he goes about arrow tuning for compounds. I am open to correction on this, but my understanding is that, assuming you can shoot well enough to tell a difference, this will only affect the width of your groups.

If you do go up a spine to 300s, these are heavier than the 400s and, according to Archer's Advantage, would come out of my bow 3 feet per second slower. Consequently, I don't think that this is the way to go to solve your sight mark issue and, if your arrows are on the weak side you can solve that by winding down your poundage a touch or putting a lighter pile in your arrow, - this last one will give better sight marks.

Also, something that might make a difference, is to opt for a lower percentage of let - off if that is an option on your bow. Again, subject to what anyone more knowledgeable has to say, I understand that that will get a bit more power from your bow.

Good luck with it,
Backinblack
 

AJ16S

Member
Thanks all - got a mixture of research and practical exercises for the weekend I think. The John Dudley website looks like a goldmine.

In the meantime I've been playing with the crono. My recurve bow, 43lbs on fingers, gives 199fps; barebow, 46lbs on fingers, gives 212fps with a med grip and 202fps with a 60mm string walk (indoor setup). The Switchback, as shot yesterday at 55lbs, was 269fps and with the limbs maxed out was 284fps - somewhat shy of the claimed 300+ by Mathews. Hmmm. Either they use a degree of, err, poetic license in the ads or I have more work to do on the bow that I was hoping...
 

Martin Heelis

Active member
Ironman
Either they use a degree of, err, poetic license in the ads or I have more work to do on the bow that I was hoping...
Nah, the speed specified is for a very specific setup. Something like 70lbs with a certain drawlength and weight of arrow.
 

T101

Active member
nothing wrong with the 400's my SB shot 400' or 300's between 54-60lbs equally well. and i could get 90m with 385g 300's @57lbs, but with sight fairly close in. peep was very low to get the right position for me though. this is more likely culprit than arrow spine.
 

Fugue

Member
+1 for the peep sight position being a possible culprit on this issue.

I'd start looking at basics before anything else.

So assuming you are completely new to the compound, check that your nock is no more than 1/8" above square, I tend to go for closer to 1/16" myself, (usually :D ). Also check that the rest supports the arrow okay and is not dropping lower than you expect. Then check your peep sight position. (make sure you are not ducking your head to look through the peep).

Are you using a wrist or hand held release? Some people using wrist release can end up with a reference point which is higher and that will impact on your sight marks.
 

jimlee

New member
. Either they use a degree of, err, poetic license in the ads or I have more work to do on the bow that I was hoping...
Ross, as Martin said earlier the quoted IBO speed of a bow is obtained using a constant set of specifications which are: draw weight 70lb, draw length 30" and arrow weight 5 grains per pound of draw weight which comes to 350 grains. When the manufacturers test different bow models for speed they will have no extra weight on the string to slow things down, ie; no nock set and no peep sight, so basically they are posting speeds that are unobtainable in real world shooting situations. The practical use of the IBO speeds is that you can compare different bow models if you need one that is faster.

Cheers, Jim.
 

AJ16S

Member
Fugue said:
+1 for the peep sight position being a possible culprit on this issue.

I'd start looking at basics before anything else.

So assuming you are completely new to the compound, check that your nock is no more than 1/8" above square, I tend to go for closer to 1/16" myself, (usually :D ). Also check that the rest supports the arrow okay and is not dropping lower than you expect. Then check your peep sight position. (make sure you are not ducking your head to look through the peep).

Are you using a wrist or hand held release? Some people using wrist release can end up with a reference point which is higher and that will impact on your sight marks.
I spent Saturday morning checking the bow against a setup guide I found on the Mathews forum (cam timing out, idler wheel out, nock too high, centre shot to the right, peep a bit high for my 80yd mark - much more to play with than the recurve so not likely to be a regular event!) Ended up with bullet holes in paper test so I figure every thing else will be me now.

Shot 80yds on Saturday afternoon and after a couple of low 30 ends, I remembered to forget about squeezing the trigger on the release to make it fire and to just wait for it to go off (not really describing that too well, since I must be squeezing it but I try to just think about holding on my back until it releases). I got into a zone where I was getting 44-46 an end until my d-loop came away (another lesson there) and I called it a day.

Anyway, now I'm happy that the bow is set up the way it should be I'll leave it alone and focus on me, cos that's where I'm going to find all the gains for the foreseeable future.
 

geoffretired

Supporter
Supporter
Sounds like you have done well, good news!
Bear in mind that the peep, at close range, will give a different alignment with the front sight, from the long range, because the front sight will be raised more.
Many archers set the peep for a longer range, as that is harder and we need all the help we can get.For indoor distances, it might be worth raising the peep if you don't shoot long ranges during the winter.
 

AJ16S

Member
Thank Geoff. Moving the peep was the hardest thing of all for me. If someone had walked into my garage after 30mins of frustration I'd have happily handed over fifty quid for them to do it! I'm sure there's a knack to it, but it did make me realise 2 things: I need a proper bow press because the Bowmaster is a pain to use; I need to make a new string because whatever is on it now is almost wool-like in consistency (and it's a horrible greeny-brown colour - anyone who knows me knows I'm very colour conscious with my archery :)
 

geoffretired

Supporter
Supporter
Heehee, colour conscious.nice! Gold alllll the way.
I don't use a peep any more but from what I remember, the movement is only 3-4mm between long distance position and indoors 20y. I left a gap between the peep and the serving above and below; that way the movement didn't produce a rotation, so no need to twist the string to realign the peep.
 
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