100 grms or 125 grms any real advantage?

[TomC1426]

I'm currently shooting an arrow with 100 grm tips and total weigh of 427 grms. It is 30.75" in cut length, shooting 4" off set vanes at 270 fps. The KE is right at 70 flbs if I've calculated correct. Now I'm thinking about going to 125 grm tips (mainly for larger broadhead), and was wondering if there is any real advantage, and what the effect on my speed and arrow drop would be.

Thanks,
Tom

[Arthur P]

In my opinion, once your arrow length gets over 30" you need a little extra weight up front. 125's will shift your FOC balance point forward a percentage or two, which will help stabilize your arrows, make them fly a bit better and be somewhat more accurate. Plus, they'll make it easier to tune your bow.

Inside 40 yards, you won't see any appreciable difference in trajectory or pin gaps.

[ButchA]

I agree with Arthur P.

Read through my posts on 100gr versus 125gr field tips and broadheads and the silly things I have done and/or caused....

With a 30.5" 2315 aluminum arrow (mine), both a 100gr tip and 125gr tip will fly very similiar at 10-15 yards. 20,25,30,on out -you'll start noticing a big difference.

You could also try bareshaft shooting with both a 100gr tip anda 125gr tip at close range and check the results.

[TomC1426]

Thanks for the info. I guess the easiest way to find out is to try it. DUD!!

Tom

[jmac_or]

typically, that extra 25 grains gets you a bigger broadhead. So, to follow on to what Arthur, you get a bit better FOC, and a bigger head, giving you a more effective hunting arrow. Better FOC means better downrange flight. Bigger head means more tissue damage. These 2 things are critical to good bow-hunting.
My $0.02
JMAC

[dick_cress]

Why not let your FOC determine the proper broadhead weight. Here is the calculation that I used to determine mine.

FRONT OF CENTER %

Arrows with a weight forward balance between 7% and 10% are the most aerodynamic.

To find your F.O.C. %


Measure the arrow shaft from the tip of the broadhead to the end of the nock. Divide this measurement by 2 to find the center point (i.e. 30"� shaft divided by 2 = 15).
Mark the center point with a felt tip marker. Now balance the arrow.
Mark the balance point with a felt tip marker. Divide the distance between the two marks by the overall length of the arrow then multiply the result by 100. (i.e. distance between the two marks of 30"™ shaft is 2.5"� then 2.5 divided by30 times 100=8.33%)[/ol]

When >10% use a lighter broadhead
When < 7% use a heavier broadhead.

My hunting shaft F.O.C. calculations.

Over all length: 30 7/16"�
Mid Point: 30.44 / 2 =15.22"� (15 7/32"�)
Difference between mid point and balance point: 2.31"� (2 5/16"�)

Therefore F.O.C. = (2.31/30.44) X 100 = 7.59%

Since 7.59 is > 7% but < 10% my F.O.C. is acceptable and aerodynamic.

Just my two cents worth.

[Arthur P]

Arrows with a weight forward balance between 7% and 10% are the most aerodynamic.

Not to sound disrespectful, Dick, but.... Says who? That sounds like an FOC setup for a FITA shooter using nib points, not a bowhunter with broadheads.

Most experts say never go below 10% FOC with a fixed blade broadhead.

The only way to find out what FOC is best for you is by trying different point weights and comparing group sizes. The weight that gives you your best accuracy is the one that gives the optimal FOC (and spine!) for your setup.

[Straightarrow]

I have to agree that high FOCs are good when shooting a broadhead. As long as the arrow spine can handle it, I don't personally think you can go too high usuing the broadheads that are typically available on the market. The next most important thing is to use helical fletching on your arrows, or one of the new wiz-bang gizmos that get your arrows spinning faster. Matching these two parameters with a good stiff arrow gives great results when shooting a modern compound with arrows equipped with broadheads.