Recommended arrow weight

[MDGrand]

So I am shooting 68 lbs with 29" draw.. arrow grain is 400, broadhead grain 100 G5.. Most bows that test over 300 fps are shooting a total of 400 grains, right? arrow weight + broadhead? I would like to stay above 300 fps.

[croix]

depending on actual arrow length (29" draw - not sure on actual arrow length) at 68# draw i think you may be under spined, but if the 400's are working for you then so be it. as for arrow weight the minimum for wa. would be 408 grns and the less you go over that the better your speed should be. that weight also happens to produce near the max ke.

[MDGrand]

But.. If I have a 400 grain arrow and a 100 grain broad head with a 29.5" arround, 29 inch draw, 68 lbs. arent I just about under 300 fps? that is 500 grains, right? I do not see many quality arrows for sale under 400 .. just thinking out loud here.. want to maxmize speed while still maintaining tolerances and safety

[Drifterat]

Are you confusing the 400 "grain" number with the number of the spine? Arrow weight is by grains per inch (GPI) and it varies with arrow type and spine. What type of arrows are they?

[MDGrand]

SH*T.. yes I am confusing it. Now I see.. I knew I had it somehow miscalculated. Thanks! I got it now.. mine are 8.5 grains per inch + broadhead comes out to abiout 345. Thanks.

[Button Nubbs]

Which bow are you shooting? Manufacturer ibo specs are done with a 35Ogr arrow 3O" draw at 7Olbs draw weight. You would be suprised how much arrow weight, draw length and draw poundage effect arrow speed. Any reason for wanting to stay over 3OOfps?

[520backyard]

SH*T.. yes I am confusing it. Now I see.. I knew I had it somehow miscalculated. Thanks! I got it now.. mine are 8.5 grains per inch + broadhead comes out to abiout 345. Thanks.

So your light if a gamie checks ya. Which they have been known to do.

[Old Dog]

  That whole set up is wrong.  You should be shooting a 340 spined shaft, and like mentioned by croix, 408 grain arrow.  I can't imagine that set up flies a broadhead very well.   Look for an arrow with a 340 spine, and around 10 grains per inch.   The broadheads are fine.

[MDGrand]

Which bow are you shooting? Manufacturer ibo specs are done with a 35Ogr arrow 3O" draw at 7Olbs draw weight. You would be suprised how much arrow weight, draw length and draw poundage effect arrow speed. Any reason for wanting to stay over 3OOfps?

Martin Firecat TR2. 29" draw. yes.. specs are for 70# 30" draw and 350 grain arrow. the reason for staying over 300 FPS.. I just want to have as flat a trajectory as I can to 40 yards.

[MDGrand]

SH*T.. yes I am confusing it. Now I see.. I knew I had it somehow miscalculated. Thanks! I got it now.. mine are 8.5 grains per inch + broadhead comes out to abiout 345. Thanks.

So your light if a gamie checks ya. Which they have been known to do.

Just checked archery regulations... 300 grains is the minimum arrow weight.. so is that the minimum arrow weight BEFORE the broadhead?

[danceswitharrows]

 
NO!!!

 

That whole set up is wrong.  You should be shooting a 340 spined shaft, and like mentioned by croix, 408 grain arrow.  I can't imagine that set up flies a broadhead very well.   Look for an arrow with a 340 spine, and around 10 grains per inch.   The broadheads are fine.

Could not have said it any better

[bonkellekter]

@ 70lbs. your minimum arrow weight (including BH, Fletch, nock, insert etc.) is 420 Gr. There is also a minimum of 6 Gr. per pound of draw weight as well

[bonkellekter]

That whole set up is wrong.  You should be shooting a 340 spined shaft, and like mentioned by croix, 408 grain arrow.  I can't imagine that set up flies a broadhead very well.   Look for an arrow with a 340 spine, and around 10 grains per inch.   The broadheads are fine.

Oops!....... yep 408 Gr. arrow @ 68lbs.

[MDGrand]

So bottom line is bought to light of an arrow to meet the 6 gr p/pound of draw weight requirement. 10 grains keeps you legal added to a 100 grain broadhead + knock, etc.. 

BTW, Old dog.. with or without broadheads from 40 yards.. shots are right on the money with the current set up.

Thanks for the info..

[halflife65]

Well, you can probably include the weight of the knock, insert and fletching, as well.

So, using weights for the nfused Axis 400 components (probably different than yours but maybe you can use as loose guidelines), you can get:
your arrow (assuming 29 inches at 8.5gr/in): 246.5gr
Insert: 16 gr
knock: 9 gr
fletching (I used Blazers at about 6gr each X 3): 18 gr
broadhead: 100 gr
TOTAL: 389.5
**I have not validated any of the weights myself.  These are just what I got from websites, so actuals could be off a bit.  I really need to buy a scale.

If you went to a 125gr broadhead you could go to 414.5.  And, if you wanted to keep your arrows and didn't mind re-fletching, you could add an arrow wrap at about 10gr making it even heavier.  However, I suspect you might already be underspined and the heavier broadhead might cause you problems.  Probably just go with 340 spine arrows.

I just felt like doing some math.  I also saw this thread and made me realize that I have new arrows this year so I better check them (mine are coming in at 412 gr).  340 spine, arrows are 27.75 inches, 100gr G5 Striker broadheads, arrow wrap, 3 Blazers.