wood arrow point weight formula

[khardrunner]

What's the formula you guys use to adjust point weight on woodies? I want to know how much to cut them down to go from 125grn to 160 grn. without messing up flight.

[dragonheart]

I shoot one arrow length that matches my draw length.  When you change the arrow length you are changing more than just the spine.  The arrow bends differently if 3 inches are in front of the bow vs. cut a 1/2 inch in front of the back of the bow.  I would decide what arrow length you want to shoot and find the best shooting arrow.  
Adjust the spine of the shaft to find the right arrow.  25 grains of point weight is about 3 pounds of spine.  From 125 to 160 for me is about 5-6 pounds of spine.

[khardrunner]

I don't have enough cash right now to play with that many arrows. So, I'm trying to use what I have and to make it work. I have some arrows that shoot relatively well at 125gr, but my broadheads are 160grn. I want to stiffen them up to take the 160grn.

Ideally I'd have the cash to mess with more arrows, but it isn't a reality right now.

[Orion]

I pretty much do what dragonheart does, and agree that 35 grains on the point equals about 5# more spine needed.  However, I overspine all my arrows to begin with and find that I can switch from 125 to 160-grain points on my woodies and it doesn't affect arrow flight noticeably.  Wood is quite forgiving that way.  Try shooting the broadheads before you do anything else.  I bet they work for you as is without cutting down the shaft length.  If not, an inch of length should do it.

[Bud B.]

If you have enough arrow length put on a 160gr point and cut 1/4 or 1/2 inch increments off until you are tuned. If you get down to too short then you know you'll need to get a higher spined shaft.

If your arrows are too short for trying the 160, then maybe see if someone in the classifieds will part with one or two arrows in the higher spine you need.

How long are your arrows now and what spine are they?

[khardrunner]

I have a test kit starting at 60-65 going through 75-80 all full length. I also have some 31" and 28" spined at lower weights but I don't know what they actually are. They shoot decently with the 125's though.

I'm shooting my 50lb@28 inch Schulz. I'm working on shortening my draw length down to around 28-28.5 inches.

[SlowBowinMO]

Shoot them with 160's first.  You might not need to do anything.

If they are a hair weak a slightly thicker side plate will take care of it.

Going from 125 to 160 isn't much, if you find yourself weak and would rather cut the arrows, 1/4 inch is probably all you'll need to take off, but thickening the side plate a hair would be my first suggestion.

[khardrunner]

Thanks!

[Fletcher]

I agree with Braveheart, mount the 160's and shoot them.  They may well shoot even better.

In general, 125 to 160 is worth about 4-5 lb, but other variables can affect that.  If you have the time and space, shoot both the 125's and 160's thru paper to check flight.  Then you will really know what is going on and you can adjust from there.

[khardrunner]

I usually bareshaft tune, but I've been unhappy with that lately. Perhaps I'll paper tune these since there are feathers already on them.

[khardrunner]

How far away should I stand to paper tune?

[grouseshooter002]

If you are showing a touch week then raise your brace height a little.

Grouse

[Fletcher]

I like to paper tune close, like 6 feet; maybe 10 feet max.  At longer distances the fletch has influenced the flight.

[deaddoc4444]

YOU say your spine  is at "full length"   on your test kit !   That would be unusual unless you  ordered them that way  MOST woodies are spined at  26 inch centers   NOT  FULL Length   so you should have some to play with    IF they are full length   they may be under spined any way and NEED a heavier weight.

[khardrunner]

No, just un-cut. They are spined the traditional way.