Change in Anchor Point Affect

[parshal]

I took another quick lesson from the folks at RMSGear the other day and found my anchor point changing slightly.  Shooting at home I noticed my arrows would sit in the target with the nock slightly to the right which, I think, indicates a slightly stiff spine.  Just for kicks, I decided to shoot through the chrony again to see if I really had changed the anchor point.  With my "old" anchor point they were shooting at 172 fps just like when I ran them through before.  With my "new" anchor point they are shooting at 178 fps.  I haven't measured the increase in draw (it's kind of tough to do myself even with a clothes pin) but moving my anchor point from the back of my jaw to the base of my ear increased increased velocity by 6 fps.  

Incidentally, changing the tip weight from 175 to 225 (I wanted to see if the arrows would stick straight as they did when I tuned them with the old anchor point) the velocity dropped back down to 172.

I'm not sure any of this means much but I just find it interesting.

[Stumpknocker]

I think it's interesting.  I have changed increased my draw length by about 2 inches by moving my anchor back to my jaw and am curious about the speed difference. Thanks for sharing.

[Stumpknocker]

Originally posted by Stumpknocker:
I think it's interesting.  I have increased my draw length by about 2 inches by moving my anchor back to my jaw and am curious about the speed difference. Thanks for sharing.

[old_goat2]

Brian, when I'm tuning a new bow or new arrow combination, which is what you kind of have since it's shooting a different speed with the same arrow, I will do like you and look to see if arrow is straight in the target. But you need to try it at different distances if you haven't already, it's possible for you arrow to start out "left" or weak and then the fletches will overcorrect it to the right and then back till it straightens it out. If you happen to be standing at the wrong distance then you might get a false indication. Theoretically if your arrows were tuned before, then increasing your draw length and consequently your draw weight then your arrows should of shown underspined.

[parshal]

That's exactly why I pulled out the chronograph.  There's no way they should be showing overspined since they're faster now.  I can only shoot 24 feet in my basement so I'll try closer and see what happens.  Once it's warm again I'll try outside.

Thanks!

 

Originally posted by old_goat2:
Theoretically if your arrows were tuned before, then increasing your draw length and consequently your draw weight then your arrows should of shown underspined.