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Discussion Starter #1
Hi All,

Does it seem strange that 20gr of point weight is making about 45 cm difference in bareshaft position at 30m?

The arrows are VAP700s so fairly light. 725mm carbon to carbon, shot at about 33lb.

Not urgent, need to be shooting better before I tune properly, but just curious as it made more difference than I expected.

James
 

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Hi All,

Does it seem strange that 20gr of point weight is making about 45 cm difference in bareshaft position at 30m?

The arrows are VAP700s so fairly light. 725mm carbon to carbon, shot at about 33lb.

Not urgent, need to be shooting better before I tune properly, but just curious as it made more difference than I expected.

James
you changing around with the plunger tension? If you don't have a clicker or inconsistency in your form. Your drawlength may be varying and that effects the drawweigth, and tune of the arrow.
Also make sure bracehight is not changing while doin your testing and comparison.

45cm seams alot, adding or reducing 20grain on my 700spine 28" shooting 38# lbs off the fingers, arrows they group slightly off. Its more like 5-10cm when i tested a month back. Going from 75gr-100gr i could hardly see a diffrence. 75gr-120gr there was a much more obvious change.
 

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Discussion Starter #3
That’s more what I would have thought. Probably form - wasn’t shooting very well today ( and I shoot with a clicker, no plunger changes).
 

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Maybe a little. The thing with adding point weight is it depends both on the weight and where on the point you add it. If the extra 20gr is just external on the tip then you get a weakening effect only. If that 20gr is in the shank then you get a stiffening effect also, which depending on the internal diameter cancels out some or even all of the dynamic weakening. Your VAPs have about the same inner diameter and weight as my ACEs so hopefully my numbers should be in the right ballpark for you to compare. My 27.5" 620s bareshaft tune well with Easton 90gr points, and adding 20gr to the outside of the point makes them about about 40cm weak at 60m. Adding 60gr, almost exclusively to the shank, using a different brand's 150gr point, gives me a bareshaft that's about 50cm weak at 70m. All of those are using a clicker and identical plunger etc settings, and are repeatable to within about 10 cm between days and using several bareshafts.

So it's not outside the realm of possibility that you got that much bareshaft movement from 20gr, but I'd recommend repeating the test quite a few times with both point weights and several bareshafts to rule out any archer effects and get a better idea of whether is was 45cm+-5cm or +-25cm, or a different position entirely and it didn't reflect the actual average bareshaft position under those conditions.
 
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