Overnight mystery bow change????

[Daveinthebush]

Yesterday the bow was shooting excellent.  Broadheads were flying as well as field points, everything was tight and secure as I checked all that in the afternoon before the evening shoot.  I even managed to Robinhood a carbon as best as one can at 40 yards in the evening.

Now today the first broadhead was 6" low at 8 pm.  The next 4 were 12" low in about the same area.  Field points seen eratic but better than the broadheads.  Everything is still tight.  The nocking loop is stationary as I have a nocking point above it to insure its location.

The only thing that I can see is that when the arrow is on the rest, the center of the knock is 1/2 inches above the center of the shaft in the rest. That seems way off.  I can not find anything, anywhere by inspecting the bow that has changed.  Limb adjustment, tiller, cams, rest, everything seems perfect.

So what happened over night.  Did the cable stretch overnight or suddenly?  I am lost.  No time to take it to Anchorage to the bow shop as I head out for a moose hunt on Friday.

[BowhunterNJ]

How old is the bow?
How old is the buss cable, control cable, and bowstring on the bow?

I'm guessing your nocking point was no where near 1/2" high before, where was it though?  1/8" high?  Even?

What could cause that kind of movement assuming everything is tight?

1) The nocking point was not tight, and moved on your draw.  Sounds like the first one at 6" moved it somewhat and the next few moved it some more.  This is my best guess based on the info provided.  You may think the nock is "tight" because your hands can't move it...but under the tension of draw weight, it may not be nearly as tight as you think.  I'd be sure to even that back out and secure it.

Because you are tight for time, keep moving it down until your broadheads come back into place.  Be sure to secure it tightly each time.  Nocks shouldn't be just "snug", they should be GRIPPING tight...i.e. clamped (assuming they are metal nocks) or served super tight several times (i.e. at least 10-14 double looped overhand knots alternating sides of the bowstring) to prevent slippage.

This tends to be a huge problem for guys, as they don't secure nocking points nearly enough...and then go to extreme such as putting 5 nocks on their string to prevent slippage.  Just secure the one on there VERY tight and everything should be OK once you even it back out so your broadheads are in the 10 ring!

2) String stretch is possible, especially if the bow has new cables/bowstring and was stored somewhere warm/hot (i.e. inside of a car during the day)

3) Something with the bow components (depending on the model) could have worn and slipped...although I doubt this and it would be quite noticeable.



But I think #1 is the culprit, in fact I'm pretty much 99% sure.

[Daveinthebush]

The bow is a brand new BowTech only 5 months old.  The knocking point did not move as the nock wear on the string is in the same spot and I can't even budge it.

String stretch?  I shoot 400-500 arrows a week right now and probably have 8,000 shots on the bow since March.

It has never been stored hot ........ this is Alaska.

Maybe I just had a real bad night and will try again today. :roll:

[BowhunterNJ]

Hrm...yeah I read your other post on your upcoming hunt...definitely putting enough shots through it well before this to stretch it out.

The 1/2" high nock is concerning though...is that where is should be?  Did your rest move down somehow?

The only things that could change are your nocking point, your rest, and your bowstring.

Stretch is obviously not likely as you have had this bow long enough and shot it enough to get the initial stretch in.

Nocking point you say appears to be in the same place on the string.

Rest?  Same place, not unnaturally low?

Beyond that...unless your cam rotated overnight somehow I can't imagine how your nocking point would move that much with all other things being in the same place.

[Daveinthebush]

Still a mystery but sometimes ya have to bite the bullet, admit the obvious, and make major adjustments only 3 days before you leave on a hunt.  I moved the nocking point down a little and adjusted the rest up.  The NAP Microtune is fantastic for centering the arrow.  Expensive at 80+$ here in Alaska but worth it.

I am back on after having to adjust my tape of range marks on the  Cobra Easyslide.  Just pealed of the tape with the yardage markings and all yardages are back on after you shoot one yardage.  Both field and broadheads are on again.  

I should have notice and it might be adviseable to keep a log for a bow.  I had been moving the sights up, ever so slightly that I had not notice the major change until I really thought about it.  Something must have been moving or changing all along, I had been adjusting for it slowly.  

Still gonna shoot every night till Thursday to make sure.

Thanks for the help.