Im shooting a Martin Jaguar 50@28 the arrows im currently shooting are Gamegetter II 2117 32" with 125 grain FT. and 4" right helic feathers. is this to stiff an arrow for my setup im drawing at 29" the arrows seem to be flying straight i haven't bare shaft or paper tested it but there is no fishtail or pourpious in the arrows. Is what im shooting the right spine or what would you guy's recommend. Thanks.
I'd say no to being too stiff.
Your overall arrow wt is probably a little under 9 gn/# draw. Maybe a little light by some standards, but if it flies good and the arrow tip is at a wt that you think you will get good penetration if hunting.
I'd like to hear some other guesstimates though.
30, In theory, yes, 2117 shafts are too stiff for your bow...BUT if they fly well and don't "clank" coming out of the bow, leave well enough alone.
2117s spine at 80# under the old AMO standard which is measured on 26" centers. That would be for a 28" arrow. So, at 32" length, you would have an effective spine of 60# for that shaft/point combination (5# per inch). Another 5# for center cut and 5# for fast flight type string (if either of these apply) and you will be right in the ball park. Not sure why you'd want 32" arrows (if you are drawing 29") but if it works, it works.
32" was just a starting point i cut 3 down in 1/2" increments to 29" and they started getting really irratic and at 30 1/2" fly great also. so im leaving them at 30 1/2. Haven't tried a heavier FT to weaken the spine some.
Throw a broadhead or two on them and see how they group with the field points. That will tell you. If the ones with bh's group separate, you are spined wrong. If they are all together in a happy little group you are good to go. If you don't intend to hut them I would say you are good to go as is.
(http://i261.photobucket.com/albums/ii45/heilakka/martin.jpg)
I've tyied using that calculator and can't figure it out. :dunno:
Looks to me like if you cut them babies down a quarter inch and you will be right on the money.
Definately try with broadheads. They never lie.
QuoteOriginally posted by metsastaja:
(http://i261.photobucket.com/albums/ii45/heilakka/martin.jpg)
I see on the chart, the insert weight for the 2117 is 16 grains, but if he is using Easton inserts, the weight for a 2117 insert is 25 grains. I have a few 2117 test arrows and their RPS inserts all weigh 25 grains.
I like the idea of bare shafting. The next time you cut a feather or wear one out, strip the shaft (better yet, three shafts) clean and compare them to fletched shafts. If they fly the same, then you are matched. If unfletch fly off to one side or the other, you have a spine problem.