FOC question

Ghost · Post by **Ghost** » Sat Sep 19, 2009 10:57 am

Is it possible to have too much FOC for the weight of an arrow.

I have 12 new Gold Tip Laser II arrows and have been shooting them from a bench rest at 20 yards. As of to day I can not get them to group well enough to calibrate the scope for these arrows. I can not figure out why they have 12 different POI, one for each arrow. The arrows are numbered and I can say that each arrow has it’s POI and usually shoots to that point. But I can not get them to all hit the same POI.

I spent an afternoon shooting 6 groups of 12 arrows, 72 arrows. Each arrow is numbered and I have 6 POI for each arrow. Each POI group was give a number and those 12 numbers are shown on a drawing that represents the one inch and two inch circles on the target.

This is 20 yards from a weighted bench rest?

The arrows are Gold Tip Laser II, weight 430 grains, are fletched with 2 inch Blazers at 4 degrees right offset using a AZ-EZ Pro fletcher. I use Gold Tip weights to add 30 grains to the insert giving each arrow a FOC of 22.5%

Crossbow is an Excalibur Exocet

Ghost

vixenmaster · Post by **vixenmaster** » Sat Sep 19, 2009 11:42 am

what type of rear nok & weight ? wraps ? sumpin jus ain't being right here. how is yer lower brace ht. ? not below the line close to riser are you ?

VixChix · Post by **VixChix** » Sat Sep 19, 2009 1:44 pm

My first thought is "check your scope mounts". Also, have you dry fired recently?

Ghost · Post by **Ghost** » Sat Sep 19, 2009 2:35 pm

nocks and inserts are the ones that come with GT arrows, I added 30 grains to the brass insert using GT screw in weights.

String is at the brace mark furtherest away from the riser.

Have Excal Vari-zone scope and yes had a dry fire last week but the GT arrows were flying in this pattern before the DF.

Each numbered arrow has a POI that in constant for that arrow. It is the same before and after DF. Have checked all screws on scope and they are not loose. Have shot over 100 arrows since DF and put xb in truck and driven over very rough fields to see if the vibrations would change scope setting. The appears to be no change in scope.

I re-fletched arrows #1,5,7.11, and 12 (see photo above) with four inch Durovanes at 2 degrees right offset. It is much windier today but the all hit in the one inch circle at 20 yards so I am thinking it is the Blazers.

I am now re-fletching two arrows with Blazers at 2 degrees right offset to see if that effects arrow flight.

Ghost

crazyfarmer · Post by **crazyfarmer** » Sat Sep 19, 2009 2:46 pm

bad day of shooting maybe.. Im usually dead center all the time, but I do have offdays where I cant group with crap:)

thats when I start blaming things but the next day groups are great again..

I wouldnt think the blazers would cause any issues. Ive been shooting those for years with the GT2's and brass fronts and I stopped shooting the same spot more than once after 2-3 arrows.

You really dont need that 30 grains up front either.. ideal FOC is 13-19%

but at 20yards it shouldnt make any difference what FOC you have

Ghost · Post by **Ghost** » Sat Sep 19, 2009 3:15 pm

crazyfarmer wrote:
I wouldnt think the blazers would cause any issues. Ive been shooting those for years with the GT2's and brass fronts and I stopped shooting the same spot more than once after 2-3 arrows.

You really dont need that 30 grains up front either.. ideal FOC is 13-19%

but at 20yards it shouldnt make any difference what FOC you have

I am thinking of pulling some of the weighted inserts and replacing them with the 115 grain inserts. Still I would think that I should get better groups at 20 yards. The four Durovanes are hiting the one inch circle at 20 yards but not the blazers???????

Ghost

VixChix · Post by **VixChix** » Sat Sep 19, 2009 4:25 pm

At 20 yard and bench-rested., hmmm.... something is wrong and I don't think it's just the overly-high FOC.

Are you using a rope cocker, or cocking by hand? If you're cocking by hand you might be cocking just a bit differently each time.

I'm still thinking that something has come loose... Double check your limbs - the little plates in the front, double check your scope. Was the scope new? If it's been on a dry-fired bow before it might have been damaged internally as well, although Vari-Zones are quite rugged.

vixenmaster · Post by **vixenmaster** » Sat Sep 19, 2009 4:26 pm

i would take off those weights & just shoot the brass inserts. you make have runout trouble causing the pt. to arrow insert to wobble. have you spun test all arrows made sure there isn't any wobbling ?

Ghost · Post by **Ghost** » Sat Sep 19, 2009 6:00 pm

VixChix wrote:At 20 yard and bench-rested., hmmm.... something is wrong and I don't think it's just the overly-high FOC.

Are you using a rope cocker, or cocking by hand? If you're cocking by hand you might be cocking just a bit differently each time.

I'm still thinking that something has come loose... Double check your limbs - the little plates in the front, double check your scope. Was the scope new? If it's been on a dry-fired bow before it might have been damaged internally as well, although Vari-Zones are quite rugged.

I am 71 years old with bad arthritis and must use the crank to cock the XB. I bought the bow new and the dealer went nuts with the blue thread lock, I may never get it apart.Ghost

Ghost · Post by **Ghost** » Sat Sep 19, 2009 6:07 pm

smokepolehall wrote:i would take off those weights & just shoot the brass inserts. you make have runout trouble causing the pt. to arrow insert to wobble. have you spun test all arrows made sure there isn't any wobbling ?

I have a high quality metal lathe. I chucked the arrows with the heavy insert and ran them in the lathe. All arrows have a little wobble compared to metal lathe specifications but no excessive wobble and some of the worst flying arrows had almsot no wobble.

Ghost

Limbs and Sticks · Post by **Limbs and Sticks** » Sat Sep 19, 2009 6:16 pm

Ghost start over either put brass inserts in or alum, do away with the added weight to me unnessary, check pts you are shooting make sure there all the same, just my thoughts on this, I couldn't get blazers to fly either, went back to 4in feathers

Wes

Ghost · Post by **Ghost** » Sat Sep 19, 2009 6:20 pm

I re-fletched arrows #1,5,7,11, and 12 (as in photo) with 4 inch Durovanes at 2 degree right offset and shot them today. It was very windy but I wanted to see how they would fly. I also did not re-calibrate the scope for these arrows. Below is a pic of that group. I shot one blazer arrow that was hitting the one inch circle to be sure the POI of the scope has not change since yesterday.

I then shot one arrow at 30 yards that suggested I needed to move the speed ring to a slower setting. Below is a pic of the group. The group is a little more open, probably due to the wind and not re-calibrating the scope.

At least I can hunt with these arrows and play the rest of the GT arrows to find out why I am having trouble with the blazers.

Ghost

Big John · Post by **Big John** » Sat Sep 19, 2009 6:48 pm

Hello Ghost:

You say you have Brass front inserts and added 30 gr. weights more to that? So you now have a 110 gr. Brass front, plus 30 gr. added weight plus a field tip of say 100 gr.? No wraps and plain fletch with aluminum rear nocks. Those are very heavy front end machines! I am going to try one and see. But that is not necessary at all. Without the extra 30 gr. those should fly like darts with 2" blazers.

vixenmaster · Post by **vixenmaster** » Sat Sep 19, 2009 6:55 pm

looks like refletched is much better, another thing to look for is make sure arrow slot is clean all the way. i do know that alot of the blazers are high enough they hit bottom of slot

Limbs and Sticks · Post by **Limbs and Sticks** » Sat Sep 19, 2009 7:24 pm

Looks like they are happy little arrows to me, GO HUNTING

Wes

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