inaccurate vortex!

[thestuz]

hey guys. i would like to point out that im newbie to crossbows but have a good mechanical aptitude and very capable of understanding the mechanics.
i plan to use these bows for hunting/target shooting and looking forward to all the mechanical spam and tips that i can get my hands on to make this thing a straight shooter.

i have recently purchased 2 crossbows. a vortex and a ecomax .
the eco max is an accurate beast but the vortex is having some accuracy issues.
i have put up some pictures that show the the arrow formations at 23yards.
the vortex seems two group high or low when stationary firing at fixed object.

the arrows are mainly "laser2 gold tip" 385grains total

vortex arrow formation at 23yards. notice the two different groupings





thb bows for comparison. the ecomax has the string suppressor and lumizone scope.
the vortex has the varizoom



so what is it that gives the different groupings?
the scope, string, arrows?

[Lucky-Dog]

It almost sounds like your scope might be jumping around on your Vortex. I guess I would double check all your bolts/screws to make sure they are snugged up. Maybe also check your scope adjustments and make sure that your windage and elevation adjustments are not sitting between a secured click position. Another thought is to swap scope assy with rings still in place together from Vortex to ExoMax and vice versa and see if problem follows.
Good luck

[wabi]

It almost sounds like your scope might be jumping around on your Vortex. I guess I would double check all your bolts/screws to make sure they are snugged up. Maybe also check your scope adjustments and make sure that your windage and elevation adjustments are not sitting between a secured click position. Another thought is to swap scope assy with rings still in place together from Vortex to ExoMax and vice versa and see if problem follows.
Good luck

Also check ALL bolts & fasteners on the entire bow (riser to rail, rail to stock, etc.).

Are the same arrows being used from both bows?

[UPSMAN]

all I can say is....you are a lucky man. Can't believe that you haven't damaged those bolts yet by shooting at the same spot. Especially at such a short distance.

[UPSMAN]

also looks like some of your vanes have taken a beating. That will also make your bolts fly erratic.

[Bullzeye]

Good eyes, not only do I see the damaged vanes now but also the arrow in the middle that is completely buried me thinks you need a new target.

[Ibex]

I had the same problem on my Ibex. It was caused by the scope mount moving slightly up and down. I removed the scope mount (not the rings) and put some on clear packing tape to make the scope mount fit tighter. This solved the problem.

Fran

[vixenmaster]

All good advice & here is abit more. Not all arrows n vanes hit the same, tune each individual arrow! Rotate vanes around while shootin mark the vane with a blk dot. You may shoot all 3 vanes as the cock vane to see which hits closest to yer aim spot

[CBRon]

At 23 feet you should be shooting into the same hole with all arrows....Thats less than 8 yards.... More tip weight and new fletching should work for you..... Ron

[pinshooter]

make sure all bolts and scope mounts are tight and thats also typical with GT 11 shafts. number them and see if they keep hitting the same spots. I can get the GT 11 to shoot well out of my vortex but I have to cull some.

[secret]

Something is loose for sure. Last year while lowering my bow a branch got caught between the scope mount and shaft and loosen the bolts holding it to the bow.

[Boo]

I'm going to agree with Ron, you should be getting one hole grouping. Try using just one arrow and report back.

[thestuz]

At 23 feet you should be shooting into the same hole with all arrows....Thats less than 8 yards.... More tip weight and new fletching should work for you..... Ron

first off, thankyou all for your replies.
secondly, sorry guys, when i said 23feet i ment 23 yards. my bad.

thanks for all the replies.
all the bolts are torqued up evenly throughout the whole bow and some are blue loctited (especially the scope mounting gear)

i am beginning to think it is a scope defect or possible arrow variations. i had 20 bolts made up and weighted evenly at around 385 grains. i have tried heavier tips but still found variations in accuracy.
the arrows with the damaged or straight veins did not appear to effect the groupings also... it was something else

one observation is that my vortex leaves a distinct sulphur smell after being fired.... i have realised that this is due to the bolt knock chafing on its way down the bow onec fired.... this is not good!...it seems to have worn away some of the hard anodizing. i have fired approx 200 shots on this vortex now.

i have decided to lightly file back the areas on the knock that come into contact with the rail and see how they shoot then. this should not cause as much wear to the rail i would assume.

this is the wear on the railing. note it is only on evident the left hand side of the railing


this is the damage to the offending knock area.you can see the wear and burn marks from the hard anodizing.


and this is the bolt knock with the offending "high" areas filed down. this should result in the carbon fibre touching the rail and not the alloy knock which should stop the melting and damage.
do you think this is a reasonable idea?
i thought of going to the trouble of replacing them all with plastic knocks but then they would only just melt down and eventually touch the carbon anyway.
this only a one off trial arrow. its almost new year over here in australia now (in 11 hours) so happy new year to you all over there and ill speak to you all next year

[CBRon]

Check your tiller...... and and measure each side along string from rail to limb tip , are they the same ? With bow drawn back measure from front screw holding scope mount to limb tip , are they the same ? MAKE SURE SAFTY IS ON......
Mark your serving with white marker on either side of rail to make sure your pulling the string back straight......
It's hard to see in the picture but is one of your dissapator pads squished more than the other ? ........ Ron

[Ont_Excal]

[quote="thestuz
and this is the bolt knock with the offending "high" areas filed down. this should result in the carbon fibre touching the rail and not the alloy knock which should stop the melting and damage.
do you think this is a reasonable idea?
[/quote]

Very bad idea to file nock.
You want maximum nock surface area in contact with the serving.
Filing the nock may cause a dry fire to happen or cause the filed nock to cut the serving.

Clean the rail and you will see that the anodizing is not wearing away.
When anodized the rail is harder than the aluminum nock and will only wear the nock slightly.

Looking at your groupings, I don't think it is the scope at fault.
A poorly mounted or bad scope would spray arrows all over the target.

You need to look at your arrows more closely.