Changing insert/point weights around - does it affect tuning?

[Gdpolk]

I'm currently running 100gr inserts and 125gr heads.  I shoot a variety of points for different purposes and wanted my setups to all shoot the same whether I was running a field point, Judo, small game hunting head, rubber blunt, or broadhead and this was an easy point weight combination to make it work with while keeping some heavier forward mass that tuned well out of my bow.

That said, I had a friend ask me if my bow would shoot the same if I ran a larger 200gr head and 25gr insert but took advantage of the larger head having more mass and length to improve penetration and durability.  I didn't know how to answer that question.  

So, does this work out only in theory where 225 up front is equal to 225 up front or does hanging the heavier head farther out mess up the dynamic spine and make arrows fly just a little off from one another?

If both the 225's up front are in the same place, it would be the same. If you went from a 200gr point/broadhead and 25gr insert to a 100gr insert with a 125gr point, the weight is still "up front", but not in the exact same place. The FOC will be slightly different, and the spine will be slightly different. Would it be enough for you to tell? Only way to know for sure would be to try them both out side by side and see.

Bisch

[damascusdave]

I doubt that I could shoot the difference

DDave

[dbd870]

I can't imagine the small shift would be enough to notice

[Gdpolk]

Time for me to bust out a couple of bareshafts!  One with my typical 100gr insert and one 125gr point and I'll rig the other with a standard insert and a point weight to bring it up to a total of 225gr.  If my buddie's theory is accurate that might make a good reason to build my broadhead arrows just a little different.  Essentially it could, if they shoot the same, allow me the opportunity for a larger broadhead that's built sturdier.  I'll report back when I'm done testing.

[forestdweller]

You would not be able to tell the difference. Even shooting bareshafts the difference would be neglibible.

I can shoot 125 grain and 145 grain field points bareshaft and can not tell the difference between 20-40 grains.

With 4" feathers I can't tell the difference probably between 125 grains and 300 grains.

It's going to come down to your form when all is said and done.

[Longtoke]

this is something I have really been wondering about. And it seems hard to track down the finer points of it. How much difference does insert length have on shafting? Surely some I would think since the shaft can no longer bend where the insert begins, not to mention shiftting foc.

That being said I have been playing around with different inserts, footings, and points,always trying to stay close to 270 total up front. I can't tell any noticeable difference on any of the builds and some are about 30 grains heavier.

If I do my part arrows fly true. If I mess up they wobble.

[Longtoke]

I have seen a few people  post that longer heavy style heads like really big vpas may need a stiffer shaft than standard field points when shaft tuning.


"Larger/longer broadheads may require a slightly stiffer arrow than perfect bare shaft. average size broadheads usually fly fine with a tuned arrow.
BigJim"


I built my carbon set around using big heavy heads though so I can't comment personally.

[ozy clint]

Longtoke is onto it. The difference in insert length has a greater effect on spine than the slight change in FOC because of the difference in the flexible portion of the shaft. I eliminate this by using a footing that is longer than the longest insert used. This way the flexible portion of shaft remains the same regardless of point/insert combo. Only the FOC changes slightly which I haven't been able to notice.

[damascusdave]

There is lots of information posted here that is not correct...I shoot short VPA 250 grain 2 blades and long VPA 250gr 3 blades interchangeably...I usually have both in my quiver

DDave

[katman]

There are lots of variables involved so you need to try it for yourself. What works for one may not work for another.

" I'll report back when I'm done testing.", please do.

[Longtoke]

Originally posted by ozy clint:
Longtoke is onto it. The difference in insert length has a greater effect on spine than the slight change in FOC because of the difference in the flexible portion of the shaft. I eliminate this by using a footing that is longer than the longest insert used. This way the flexible portion of shaft remains the same regardless of point/insert combo. Only the FOC changes slightly which I haven't been able to notice.

That is a good idea about using the footing to even out your different arrow set ups.