Arrow Weight Question

Discussion in 'Tech Talk' started by Brian J Krueger, Apr 7, 2021.

  1. Brian J Krueger

    Brian J Krueger Newb

    Joined:
    Apr 7, 2021
    Posts:
    4
    Likes Received:
    1
    Dislikes Received:
    0
    Alright so my current specs of my bow : VXR 31.5 at 30in DL and 70 LB.

    I have Easton Axis match grade arrows 300 spine at 31 in length with 5.5 in wraps, blazer vanes, nokturnals, 50 grain brass HIITs, and 100 grain broadhead/fp. This comes to around 520 grains. I'm worried this is a little too heavy, and I'm wondering if going back to the standard inserts would be best (roughly down to 486 grains then). What do you guys think of this setup? Any advice?
     
  2. Fix

    Fix Grizzled Veteran

    Joined:
    Apr 27, 2016
    Posts:
    6,213
    Likes Received:
    7,141
    Dislikes Received:
    23
    Location:
    Western NY
    https://archerycalculator.com/arrow-front-of-center-foc-calculator/
    Here is the calculator for FOC.
    I don't think you have any reason to lower your weight. You have the rig to push well into the 600 grains without slowing down too much. Give it a try and tune it. You may be pleasantly surprised. Your goal should be finding a sweet spot of weight vs speed. Explore your set up and realize it's limitations and preferences. Good luck and let us know what you find
     
  3. Fix

    Fix Grizzled Veteran

    Joined:
    Apr 27, 2016
    Posts:
    6,213
    Likes Received:
    7,141
    Dislikes Received:
    23
    Location:
    Western NY
    Side note though, your spine is not correct for the fore mentioned set up.
     
    dnoodles likes this.
  4. Brian J Krueger

    Brian J Krueger Newb

    Joined:
    Apr 7, 2021
    Posts:
    4
    Likes Received:
    1
    Dislikes Received:
    0
    Yes I think I could fall into either category.. I know it probably leans towards the 260 spine slightly, but that would've just added more weight. Do you think this will hurt me?
     
  5. Brian J Krueger

    Brian J Krueger Newb

    Joined:
    Apr 7, 2021
    Posts:
    4
    Likes Received:
    1
    Dislikes Received:
    0
    It looks like the FOC % is somewhere between 10 and 11 %
     
  6. dnoodles

    dnoodles Grizzled Veteran

    Joined:
    Oct 13, 2012
    Posts:
    8,729
    Likes Received:
    10,151
    Dislikes Received:
    13
    Location:
    People's Republic of IL
    Negative, you will be fine in TAW but as Fix said, you are a bit under spined. If you don't want to spend $175 on a new arrow set up you could drop 5-10lbs in draw weight and your spine should be OK.

    It's pretty much always better to be a bit spine heavy than too light.
     
    Fix likes this.
  7. Fix

    Fix Grizzled Veteran

    Joined:
    Apr 27, 2016
    Posts:
    6,213
    Likes Received:
    7,141
    Dislikes Received:
    23
    Location:
    Western NY
    General rule I like to follow is if you add weight up front(front load) you need to stiffen up one level so I think he may need to up his spine by 2 to tune but only through experience will he know
     
    dnoodles likes this.
  8. dnoodles

    dnoodles Grizzled Veteran

    Joined:
    Oct 13, 2012
    Posts:
    8,729
    Likes Received:
    10,151
    Dislikes Received:
    13
    Location:
    People's Republic of IL
    I shoot same DW and DL in a 340 IBO rated bow shooting 535gr arrows with a lot up front.

    He should be fine with a 250 spine or drop down to 60-65# with the 300s. I used to shoot 300s and I was good at 65. But I didn't have quite as much up front.
     
  9. Mod-it

    Mod-it Die Hard Bowhunter

    Joined:
    Mar 28, 2019
    Posts:
    1,020
    Likes Received:
    1,331
    Dislikes Received:
    2
    Location:
    Idaho
    Spine charts recommend a 250 spine for your specs and that's with only a standard 12 grain insert. By adding 50 grain inserts your spine is even more weakened.
    With that being said, I'd first see if they'll tune the way you have them. I have some 3d arrows that are 400 spine, they show weak in a chart at my specs (way shorter DL than you at 27.5") but they tune in for me and I group them fine.
    Dropping the 50 grain inserts is going to drop your FOC to a marginal point. May tune, may not. It will improve possible spine problems, but may bring too low of FOC problems into play. You're around 10% right now, going to a 12 grain insert will put you around 6.5% FOC. I personally like to have a minimum of 7.5%, I just seem to struggle if FOC gets much lower than that.
    Playing around with a spine calculator, here's what I personally would do if in your situation and they won't tune as is:
    My first step would be to drop my draw weight to 65 lbs. See if they'll now tune.
    If no, then I'd cut the arrows to 30" in length. Glue in some "standard" 12 or so grain inserts that would accept the Goldtip F.A.C.T. weights. Try to tune with a 20 grain weight added to the back, if still no then I'd try a 10 grain weight.
    I think somewhere in the above steps they'll tune. The only other thing, besides dropping draw weight even more, would be to try a standard nock to see if improved FOC helps. I think spine will come in with the above changes, but then FOC problems could...maybe...come into play. Your Nocturnal nocks weigh around 22 grains, going to a 10 grain nock jumps FOC a whole 1.5%.

    Another option if they won't tune as they currently are:
    Remove your Nocturnals and sell the arrows. 31" is enough for 80% of archers out there to cut them down to fit their shorter DL, I think you'd have no trouble selling them.
    Buy some in a stiffer spine and move on.
     
    Brian J Krueger and Fix like this.
  10. Brian J Krueger

    Brian J Krueger Newb

    Joined:
    Apr 7, 2021
    Posts:
    4
    Likes Received:
    1
    Dislikes Received:
    0
    Thank you all for the responses. It sounds like I may have some small tweaking to do. I did just double check the length of my arrows, and carbon to carbon they are 30 in actually (a little over 30 in to belly of nocks). This helps a little, but sounds like I still may be slightly underspined with the weight up front.
     
    Fix likes this.
  11. Travis Choate

    Travis Choate Newb

    Joined:
    Apr 7, 2021
    Posts:
    7
    Likes Received:
    1
    Dislikes Received:
    0
    Location:
    Angleton Texas.
    All ways go up with the weight of your arrow never down a heavy arrow set up is the only way to go.
     
  12. Travis Choate

    Travis Choate Newb

    Joined:
    Apr 7, 2021
    Posts:
    7
    Likes Received:
    1
    Dislikes Received:
    0
    Location:
    Angleton Texas.
    You probably need to go to a stiffer spin on your arrows
     

Share This Page