different point grain weight for different arrow length ?

[Pequa1]

Opinions please-
I have a 28" draw, am using a 40lb Martin Jaguar TD recurve.
1916 aluminums seem just right, spine-wise.
I recently obtained some 30" 1916s that I intend to mount broadheads on.
( I could cut them down another 1/2", undecided on that so far.)

Here is the question:

Although I realize the different aerodynamics of a broadhead will be involved, even if mechanicals are used, should I use a lighter or heavier point on my 28inch target arrows, to approximate roughly the same point of impact with 100 grain broadheads on the longer 30" arrows, using the same instinctive style point of aim ?

Or, should I switch to 125 grain target / field points on my shorter arrows and use 100 grain broadheads to have them all (both 28" target arrows and 30" broadheads, approximately on target.
(Will that extra two inches make that much difference ? (no snide comments please, lol !)

[McDave]

The problem is that you have two different things going on.

You're considering using two different point weights, and two different arrow lengths.  Both of these will affect arrow tuning.  In order for a 28" arrow to be tuned the same as a 30" arrow, you would need a heavier point on the 28" arrow, assuming both arrows are the same spine.  Tuning affects arrow flight mainly, but also will affect the point of impact of the arrow.

In order for a 28" arrow to have the same point of impact as a 30" arrow, assuming both were tuned for your bow, you would want them to weigh about the same.  The 2" of shaft wouldn't weigh enough to matter, but 25 grains of point weight would be enough difference to make one arrow impact lower than the other.

Since you're combining two changes that might each have different effects on the point of impact, you probably just need to set up your different arrows and shoot them together in order to see what happens.

I had a similar situation, where I had a bow set up to shoot targets, so cut the shafts to 28", which is about my draw length.  When I decided to hunt with that same bow, I needed another inch of shaft length so the broadhead wouldn't hit the riser.  I shot enough 28" and 29" arrows, both fletched and bare shaft, that I convinced myself that within my capabilities of shooting, there wasn't enough difference in point of impact to worry about.  But I was using 125 grain points/broadheads on both arrows, so I didn't have that variable to worry about either.

[Paul WA]

I shoot different weight arrows for targets than I do for hunting, actually different spines. I am not concerned with equalizing point of impact as much as obtaining perfect arrow flight...PR

[Pequa1]

Thank you gentlemen.
I have just gotten back into this sport after over 40 years away.  I wish the ability to help each other out like this existed back then- my sons have no idea, lol.
Anyway, I think what I will do is put my 125 grain field point on my 28" arrows, and the 100s on my 30" arrows, and see how they fly.  To make matters more complicated, one set of the arrows are 4- fletched.  However, I think since I am a returnee and not all that consistent as yet, I will be shooting at just 20 to 30 yards for quite a while, so maybe "elevation" will not be as much of an issue as my "windage."   Thanks again.

[xtrema312]

I think the best approach is to bare shaft the hunting shafts using field point to get your tune.  Then change to broad heads and fine tune. Take note of the tune settings.  Do the same with the target arrows.  Take note of the tune settings if the nock set and brace height are different.  Shoot targets until it is time to practice for hunting then change arrows and tune.  I have a hard time shooting two totally different arrow lengths and head weights because I find neither arrow is tuned as good as I want.  I can do it, but it is not ideal.  I was working with a new bow tonight and found two arrow set-ups with the same spine, but they were best with about 1/8” difference in nock set.  I got great groups with one setting for shaft one and the other setting with shaft 2.  I shot ok in the middle with both, but it was a compromise.