Buying new FMJ's. Help me think through this.

[Stoof]

I had some FMJ's given to me. 3-340's and 3- 400's. I have been shooting them as a mixed bag when I practice but using the 340's to hunt. I'm going to buy 1/2 a dozen more tomorrow so I got the wise idea to french tune or simply shoot at a string at 3 and 9 yds. The 340's are busting the string and the 400's are about an 3/4 of an inch left at 3 and an inch plus at 9, so that tells me what the bow likes.
So I get on the Easton website and their calculator tells me with a 29 inch arrow, 62#'s and a 125 gr broadhead to shoot the 400's. If I did it right. Go 340? or 400 and re tune?
Anywho,
I also am wondering if I should cut them a little shorter. The arrows are 29 inches which is about 3 inches past the Whisker B. and about a half inch past the shelf.
Any advice is much appreciated.

Cheers,

[hoyt21]

340

[careybirdwell]

I just went through the same thing with the Carbon Express Maxima Blue Streaks. On the general arrow selector guide, it would tell me to shoot the 250 (400) but my bow shot the 350 (340) much better and my grouping was so much better with the heavier arrow. I went with the 350 (340)

[enewman]

I looked at the Easton bow hunting chart.

With out knowing what bow. I used the ibo of 301 to 340. I made no adjustments for brace height. And chart stated j. Which is a 340 spine.

If you was to cut two inches off then yes the chart would put you in a 400 spine.

But your asking for opinions. So even if I was to cut the arrow a little shorter I would still use a 340 spine.

[Stoof]

I looked at the Easton bow hunting chart.



With out knowing what bow. I used the ibo of 301 to 340. I made no adjustments for brace height. And chart stated j. Which is a 340 spine.



If you was to cut two inches off then yes the chart would put you in a 400 spine.



But your asking for opinions. So even if I was to cut the arrow a little shorter I would still use a 340 spine.

Shooting a BT General so IBO is 315. Good guess! I feel like I could easily lose 2 inches off the arrows and be GTG.

Thanks.