Differences in Bolt Point of Impact

[tex45acp]

I have been shooting my new Axiom for a couple of weeks now and am amazed at the consistent accuracy, even taking the bow off the frame and reassembling it several times. The 20" Firebolt carbon arrows and 150gr field points, that came with the package are tack drivers. Last week I bought six 20" Lumenok arrows and 150gr Boltcutter broadheads. I changed out the field points on the Firebolts with the Boltcutters and the arrows shot to the same point of aim. I did the same with the Lumenok arrows and they shot consistently 3" low and 2"-2.5" to the left, but in a tight group. I have never in 25years of Bowhunting had that much variance in this kind of change. I plan on readjusting the scope to match the Lumenok arrows since I plan to hunt with them this weekend. Any suggestions as why the Lumenok arrows shoot to such a different point of impact?? I know they weigh 319gr. without broadheads. I was thinking of trying a 100gr. or a 125gr. broadhead to see if that makes them shoot any closer to my existing point of aim. Any ideas would be helpful!!

[newbie]

by my supurb math skills they weigh 69 ish grns more then the firebolts. Sight it in with your hunting arrows and good to go.

[wabi]

In my experience an often overlooked variation can have a big impact on arrow flight - the helical of the fletching!

Weight is an obvious factor, FOC can be a factor that is commonly pointed out, but fletching & the helical (or offset) of the fletching is seldom mentioned. It, too, can make a big difference.

I'd just sight in with what I plan to use for hunting and stick with that brand of arrows in the future if they do what you want.

[Kegbelly]

JMO but the added weight of the luminok on the back of the arrow seems to exaggerate the planing or steering effect of some broadheads. It made a difference with mine, YMMV. That extra weight on the back changes the balance of the arrow and FOC, in my experience it was a very noticeable change. If your lumenok-equipped arrows are grouping tight but your POI is off, adjust the scope to bring them back to your POA and stick with those arrows for hunting.

[tex45acp]

In my experience an often overlooked variation can have a big impact on arrow flight - the helical of the fletching!

Weight is an obvious factor, FOC can be a factor that is commonly pointed out, but fletching & the helical (or offset) of the fletching is seldom mentioned. It, too, can make a big difference.

I'd just sight in with what I plan to use for hunting and stick with that brand of arrows in the future if they do what you want.

I was looking at that as well. From what I can tell with my old eyes, there is NO helical. The vanes are straight. I might take one of them and strip the existing vanes and install new ones with a slight helical to see if that makes any difference. Since the Cock vane rides in a channel, I can't do much.

[nchunterkw]

Many on here use 2" Blazers (or similar) and install them with an Arizona EZ Fletch Bolt fletcher. It puts on a TON of helical and that helps to stabilize things very well. My thought on the POUI difference is in agreement with Kegbelly. The Lumenoks are around 30gr each which is much heavier than the other nocks. This changes the FOC which changes the arrows trajectory. And as you have already heard, since they group well, just sight in with them and then enjoy some backstraps. Well, you DO have to shoot one first.

[awshucks]

Since the Cock vane rides in a channel, I can't do much.

All three vanes can 'ride in the channel' if you have flat nocks. Good luck!

[Pintail]

The lumenoks are in the ballpark of 28 grains give or take. That amount on the very end of the shaft will have a stiffening effect on the dynamic spine of the arrow. I believe even though we are shooting off a "rail" flight characteristics relating to spine and front of center are somewhat the same as with any longbow or recurve. If you had good flight before adding the lighted nocks you may want to experiment with adding 28-30 grains on the point end to see if things come back your POI. Some archery shops like 3-rivers sells brass washers that can be placed behind the point or broad head for this reason.

[paulaboutform]

Full agreement with Kegbelly also. My findings have been the same.