Thread: Arrow Weights

In another thread, I had, over time, expended a lot of keystrokes, on the myriad issues of NZPost and the delays, that their marketing Foofs had tried to minimise.

On Friday the the little jeweller's digital scale, I'd ordered back on April 5, turned up. 4 months + really?

Now I can weigh my arrow shafts and points etc.

The following may not mean much, but it helps me understand how arrows fit into the consistency part of accuracy.

I'd got 3 sets of arrows:

A. 1 set of 6, 500 spine, came with the bow

B. 1 further set of 6, 500 spine

and C. 1 set of 12, 400 spine.

Whilst waiting for my scale, I'd made an arrow spinner. Rough and ready this spinner allowed me to see which arrows spun pretty well and which wobbled all over the place and were really, not straight.

Set A, only 1 of the arrows spun well, set B, 5 of the 6 were good, and set C 8 of the 12 were good. So on straightness, I've got 14 from 24. mmm, cheap arrows...

Now to the weights - all of the following are total weights, each including nock ~20gr - point ~100gr - and fletching ~10gr:

Set A - all over 528gr and up to 576gr
Set B - all 6 from 543gr to 545gr
Set C - the 12 ranged from 443gr to 476gr

Something I've read: "My personal setup now is a PSE Carbon Air set on 58 pounds at 29 inches with a 438-grain total weight arrow, which includes a 165-grain, all-steel Bipolar head and an Ignitor lighted nock in the rear.
This setup shoots 281 FPS and creates 76.6 foot-pounds of kinetic energy with awesome momentum."

I've also read that for hunting, heavier is better, for target, lighter is better: "Heavier arrows are slower but absorb more of the bow’s kinetic energy. Bowhunters often choose heavier arrows for deeper penetration and better wind-bucking traits. Because heavier arrows absorb more energy, they’re also quieter to shoot."

My first surprise was that the 400 spine 12-set, were significantly lighter than the 500 spine sets. What I've read was that they should be heavier, i.e. larger spine number = smaller grains per inch number.

The second surprise was that set B were almost matched in weight.

Not surprised that set A, that came with the bow, were the least straight and most variable

Conclusion on weights and straightness:

I've got 1 arrow from set A that I'll use for testing.

There are 5 arrows from set B that are almost matched, so I'm gonna use them for target and so.

I got a nearly matched set of 6 from set C that I'll use for hunting hares and such when I'm accurate enough. I think I know why set C are so light, no paint! Bare carbon finish. I do have some of those dinky shrink wrap arrow wraps, @ 13gr each, so I may put one of those on each of the 6 from set C, along with a heavier small game point @ 125gr which will help bring the weight up.

Grains per inch: measured without nock, point and fletching, so total weight - ~130gr in my arrows.

archery360.com - says "a light shaft weighs 5 to 6 grains per inch, a midweight shaft weighs 7 to 9 grains per inch, and a heavy shaft weighs 10 or more grains per inch."

Set A and B the 500 spine arrows are all ~ 13gr per inch, quite heavy ? or not...
Set C, the 400 spine arrows are ~10gr per inch which seems about right according to what I've read.

FOC front of centre, I read: "an FOC between 11 and 15 percent is ideal for hunting setups and will help accuracy at longer distances."

My set B is 7.5%

My set C currently is 9.1%

Now I'm wondering whether or not I get into Kinetic energy and so on. I'm also thinking that maybe I have to standardise the arrows, before I can fine tune the bow, which as noted in the Cam Timing thread, is still being adjusted