How many grains before you see a difference in arrow flight?

[BassBow]

Tuning up some new arras and getting a lot of great advice on arrow tuning. I bare shafted with 145gr and was challenged to up it to 175gr. The flight is still very good. How many grains added or subtracted does it take for you to notice spine issues?

Thanks!

[lpcjon2]

For most experienced gents a 10-15grn difference may be noticeable. most likely 20+ gr will start to show some differences.

[Bladepeek]

I think part of the answer may depend on the bow's cut to center.

I have a long bow that is about +1/4" from center and it is really fussy between 145 and 175 gr. Another bow, cut -3/16" past center, just doesn't seem to care too much what I shoot from it. Same for arrow spine.

[ISP 5353]

Lots of variables to that question.  If the bow is close to centershot you may see very little difference in flight even with pretty big changes.  On a shallow shelf longbow tip weight can really make a big difference.

[McDave]

I would see a lot of difference in the bows I shoot between a point weight of 145 and 175.  This includes bows that are cut past center as well as longbows that are not cut to center.  Not that I couldn't do it; just would have to re-tune the arrow.

[Steve Clandinin]

The efficiency and weight of your bow will also come into play.I don't notice much between 175 and 200 grains.What I usually shoot.Bows between 55 and 60#.

[ron w]

What Bladepeek said......

[BassBow]

Very interesting. Thanks, gentlemen!

[gonefishing600]

In my experience, if you can't tell the difference between 145gr and 175gr, your right where you need to be. The fine tuning can be done with brace height, and string silencers.

[dhermon85]

I can bump 50 grains in a longbow and not notice a difference, but out of curves with different cut will show a lot.

[Yellow Dog]

Depends on the bow and how the riser is cut but usually around 25 to 30 grains with broadheads for me. Your milage may vary.

[Steve O]

I get the same as Mike on most of my bows; 25/30 grains.

[Roger Norris]

25/30 for me also, although I find carbon shafts to be the least sensitive.Cedar shafts seem to be very critical of point weight for me.

[ozzyshane]

Rogar i find the same thing with carbons but the length is a big thing with the carbon compared to allie shafts Thnaks Shane

[damascusdave]

Those kind of questions always give me a headache which I cure by shooting arrows that are not tuned quite as well as they might be...I call that practicing or conditioning...when I go hunting I take well tuned arrows

DDave

[Burnsie]

May also depend how close you are on either end of the spine spectrum.  If your arrow appears to be tuned well but is actually pretty close to being on the underspined side of things,  it may not take much more weight to put you over the edge - and vise-versa if your leaning more towards being on the stiff side of things.  But,  I agree with about 25-30 grn if you have things dialed in right down the middle.

[Friend]

From my perspective -

How much one's set-up is centered within a tolerance band for nice flight will dictate how many grains may be added two or removed and still maintain adequate flight.

Example: A centered set-up(perfectly tuned arrow) may permit up to +/- 3.5#s in dynamic spine and still yield nice arrow flight. Approximately 1# of arrow dynamic spine is equivalent to 6 grains.
Six gns X 3.5#s would = 21 grns.

The optimuized arrow flight in this example would permit up to +/- .021 variance and yield nice flight. If one's set-up required an additional 15 gns to center his process(optimum flight),then theoretically the set-up may tolerate the 15 gns in addition to a .021 gn increase and still obtain nice flight.

My own experiences do not refute the above findings, yet I have ascertained that the estimates are well w/i the playing field.

I still project that optimum arrow flight does not find itself positioned as the nominal spine value between too stiff and too weak. Weaker spines have exhibited more forgiveness vs. stiffer spines as observed relative to seemingly optimized bare shaft flight at 40 yards. Note: Achieving true optimized flight is impeded by my less than desirable shot execution.