Arrow spine????????

BuckGrunt · Jan 23, 2007

Im needing some opinions about a question on arrow spine.Heres my current set-up. Mathews Switchback xt draw length 29" @66lbs
im shooting gold tip xt hunters(5575) with.400 spine and 125grain tips.My question is if you go on goldtip.com and look on the chart they have it shows I should be using xt hunter (7595) with .340 spine........Should I be looking at buying some new arrows?Would the wrong spine show in bad arrow flight?

BigPig · Jan 23, 2007

LAST EDITED ON Jan-23-07 AT 08:26PM (MST)[p]LAST EDITED ON Jan-23-07 AT 08:26?PM (MST)

Without looking at the exact numbers you sound underspined and would be better off with 7595's. Or maybe shoot 100gr heads. With your current set up, your arrows are not quite as stiff as they need to be to push 125 gr heads. You may visually see some fishtailing and it may not shoot through paper well, probably showing a left tear. Furthermore, your broadheads may not shoot to the same point of impact as your field tips, probably grouping to the right.

beaner · Jan 23, 2007

Had same issues when I converted to carbons. I just lightened the broadhead to 100 grains and they were flying like darts w/o the fishtailing. Broadheads were easier to replace than carbon arrows IMO.

Good luck.

a3dhunter · Jan 24, 2007

LAST EDITED ON Jan-24-07 AT 12:33PM (MST)[p]Another option would be to decrease your draw weight to 60 lbs.
You mentioned your draw length is 29", are your arrows cut to 29"? The length of your arrow also affects spine, if your arrows are cut to 28" they should be fine. That being said I have heard it is better to go with a size stiffer if shooting 125 gr. heads.

I checked the Gold tip website and from what I saw either get stiffer arrows or drop you weight on you heads(like stated above).

swbuckmaster · Jan 28, 2007

Selecting arrows can be tricky sometimes especially when you are on the edge of spine chart. You stated you are using a 125 grain tip! I assume it is just your broad head= 125. You also need to take into consideration your insert weight= another 15 grains. Your tip weight would= 140 grains.

140 grain tip out of 29" standard GT arrow with a 4? fletch and GT nock out of a 66 lbs bow would be under spined.

However you could add weight to the back of your arrow and it could work out with your 5575's. You could add 26.2 grains for a lumenok, 8 grains for an arrow wrap, and 24 grains of 4" fletchings would give you a 436 grain arrow with a front of center of 10.13%, I believe this would work for your set up and would be an arrow you could recover quit easy after a miss or a hit. This set up would have more kinetic energy and a quieter bow.

If you are concerned about spine on that set up then go with the 7595's, 140 tip and insert, 15 grn blazer vane, 12 grn GT nock, with a total weight of 425 grn and a front of center of 13%. A little more weight on the front of a stiffer spine arrow will soften it up better as well as be more stable in flight with a broad head. This set up would be 3 feet per second faster than the 5575 set up.

Either of these set ups would work with your bow!