Arrow Speed vs Arrow Weight

[Roy Steele]

If your shooting 3D as light as your bow will let you.But I like to shoot my hunting weight all the time.gain I shoot as heavy as me and my bow feels [shoots] confordable with.Use'ly not as heavy as I could go.You and your bow have work that one out.

[O.L. Adcock]

Wingnut is correct, trying to compare compounds to stickbows, they have a lot more horsepower for the same peak weight, yet the "speed" they try to push hurts their penetration potential.

At 200fps your margin of error on a deer sized target at 40 yards is plus or minus 1 yard...At 250 fps it's 1.5 yards...

The way bows work, compounds included, if you increase arrow weight 100% you lose 25% of your velocity. So those worried about trajectory changes with 20% arrow weight changes, you're only looking at 5% velocity change.

Many are missing the point of the Ashby studies. His earlier studies looked at mass weight alone with broadhead design without taking FOC into consideration. Conclusion....More mass helped...

When looking at FOC, more FOC helped...A LOT! So much so an arrow at 8-9gpp with a high FOC (over 20%) will out penetrate an arrow in the 12-14gpp with a more typical FOC of 10-15% by as much as 100%...

So...Don't link high FOC and "heavy" together, they are seperate. You can shoot high FOC's at 7gpp if you want.....O.L.

[Jason Jelinek]

O.L.,

I'm a believer of high FOC for non-bone hits, but when it comes to bone, mass is the key (at least that's what I read in the Ashby reports).

Jason

[O.L. Adcock]

Yep, 650 grains with a high FOC is the heavy bone threshold no matter what weight bow it's out of....O.L.

[R H Clark]

O.L.,

Does that margin of error stay at the same ratio for a bow shooting 200 fps and one shooting 150?

Any info on how that half yard equates to inches on a target?

I would be very interested to see how 20-30-50 fps changes the arch of trajectory at say 30 yards in inches lower on a target.

It would be interesting to see exactly how much X fps would change the point of impact on a target that had been over or under estimated by 5-10 yards.

[Shawn Leonard]

The bows weight has little to do with it, it is the bows effiency. A 40# bow shooting 8gpp. is as fast as a 60# bow of the same design shooting 8gpp. I always get a kick out of people saying that is fast for a 40# bow, doesn't matter if the 40# bow will do 200fps. at 8gpp. the 60#er will only do the same at 8gpp. I find for me, my minds eye likes an arow going around 190-195fps. and with my 3 main bows that translate into an arrow that weighs just a tad over 9gpp. I get the trajectory I want and still get enough energy to kill anything in North America out of my 51-54# bows. Shawn

[wingnut]

Well as a reformed pro compound shooter, I can tell you that if you at 5 yds high on your yardage you are going to catch a high 8 on a McKenzie target, if you are 5 yds low you will likely catch a 5.  That is at 312 fps with a 5 gpp ACE arrow.

If you want to hold the 10 ring, you'd better be within a couple yards on the high side and a yd on the low.

The 12 ring . . .well you know the answer.

Now take that down to 180 fps and the yardage tightens a bunch.

Mike

[NorthernCaliforniaHunter]

Fear not Toby, for I see the light!

[O.L. Adcock]

RH, There are some external ballistics charts like on the Jackson site that would give you inches of drop. These assume perfect tuning, releases, and smooth wind conditions. Under those conditions a high FOC and a low of the same weight and external variables would fly the same. Real world the high FOC's will shoot much flatter and drift less. Interesting to look at however....O.L.

[R H Clark]

Thanks O.L.
I'm not familiar with the Jackson site but I'll do a search.

I'm starting to be more interested in high FOC.I'll have to try and find a shaft light and stiff enough to get high FOC and still stay around 8 gpp from my 52 @ 29" recurve.I'm shooting a 30.5 inch .400 now with 125 grn tips.It is tuned to group bareshafts and feathered arrows as far as 30 yards.

[wapitimike1]

Lighter fast arrows and sharp broadheads all day long. Just say no to the chugging log!!