Standard length to cut for equal stiffness between spines?

[Etter]

So my go to bow is a black widow PA. 60" and 57@29 but I only draw about 26 or so. My regular arrows are 28" 5575s with 300 grain point. I have a bunch of 3555s laying around and am wondering how short Id need to cut these to shoot from the same bow with the same point weight. Is it possible to cut a 3555 that much and have them work?  Is there a standard length on carbon arrows that can equal the exact stiffness between different spines?

I can always cut 1/4" at a time and check but itd be nice to get close without all the hassle

[McDave]

I don’t know the answer to your question.  I would just have to experiment around until I found equivalent lengths, as you suggest.

However, I do know that arrow length affects sight picture, and therefore changes your point-on.  This is obviously important to a gap shooter or anyone who consciously notices the sight picture in aiming instinctively.  They say that even an instinctive shooter who doesn’t consciously notice the sight picture is affected by it, since the subconscious takes the sight picture into account.

Shortening your arrows increases your point on, which may or may not be important to you.  However, many bowhunters on here are looking for ways to decrease their point on in order to get the arrow point closer to the spot they want to hit at hunting distances.

[Orion]

You're drawing about 50# or less at your draw length now.  If the 28-inch 55/75s with 300 grains up front fly well, you may not be able to cut the 35/55s short enough to make them work with that much weight up front.

If you plan to put broadheads on them, probably can't cut them shorter than 27 inches. I suggest cutting just one arrow to 27 inches, and experiment with point weight to determine how much you need to get good arrow flight. My guess is it will be quite a bit less than 300 grains.

[cacciatore]

One inch less means a lot for carbon arrows, not particularly expert with GT but I think that something between 1" to 1-1/2" shorter can make them right

[Etter]

Ill monkey around with it. I could go down to 200 up front but I like heavy arrows.

I shoot split finger and completely instinctive so sight picture isnt a concern

[Sixgun]

The only thing I could think of would be to use an arrow spine tester.

Use your current arrow (5575) and measure the deflection, then use the other arrow (3555) and slowly cut it until the deflection matched. That would get you close and only require one arrow to test.

Ray

[McDave]

Originally posted by Sixgun:
The only thing I could think of would be to use an arrow spine tester.

Use your current arrow (5575) and measure the deflection, then use the other arrow (3555) and slowly cut it until the deflection matched. That would get you close and only require one arrow to test.

Ray

I don’t think that would work, because an arrow spine tester measures static spine, which is built into the arrow shaft and never changes.  Here, we’re talking about dynamic spine, which is how much an arrow shaft bends when it is shot at a certain force with a certain weight on the front of it.

[Butch Speer]

I shoot 35/55 GT arrows 28" with 250 upfront from a Leon Stuart recurve 50lbs.@27"  Draw to 27"  I also shoot 55/75 30" with 250 upfront. Both shoot very good. FP or BHs.

[Fun4all]

My set up is a 64" Toelke whip longbow 48"@28" three under.  And a 60" Widow PSA 45@27" three under.

I shoot 28-1/4" bop for arrow spines 600, 500 and 400.

The difference is what is up front on each arrow spine.

The 600 has a 25 grain insert, 1" 18 grain footing and 145 grain head. 470 grain total weight

The 500 has 25 grain insert, 1" 18 grain footing and 175 grain head. 505 grain total weight

The 400 has 25 grain insert, 1" 18 grain footing and 200 grain head.  525 grain total weight

The bare shafts with a good release fly as straight as the fletched arrows and group with the fletched arrows.

I have added weight to the shaft by inserting multiple strands of monofilament weed cutting line.

Both of these bows shoot all of these spines the same. I got to this set up through a lot of shooting, cutting, insert weights, head weights, etc.  So before doing a lot of cutting do a lot of component changing around before you start making length changes to the arrows.