RE: OVER-Spined?
 

TFOX.....That's interesting stuff.

Thanks.

RE: OVER-Spined?
 

Jeff - I can see you are one of those inquiring minds type of guy. Try this: take one of your super stiff arrows and remove the fletching. Shoot it (field point only - no broadhead) at your target at 20 yards. The overly stiff arrow should hit to the left of where a fletched shaft hits,and will likely be angling into the target tip left. This is the tendency the fletching has to overcome to get straight flight. If your arrow was too soft, you would get the same issue only the bare shaft would be angling to the right. Wouldn't it be more efficient if the bare shaft was hitting right where the fletched ones hit?

RE: OVER-Spined?
 

Jeff, at 20 yards, 300 fps it's even more critical. That arrow has to become stable VERY quickly.Everything is amplified w/ speed. Every small form flaw, twitch....the faster the arrow is flying, the less forgiving it is. Now add to that equation an arrow that's not spined correctly for the bow (either over or under) and it's less forgiving still.

There are ways to get the weight you want w/out overspining yourself. Let's just say you need to shoot ACC 3-60's to get the proper spine for your set up, but they are too light for what you want. BUT, the 3-71 is the weight you want, but it's overspined. Ok.....don't cut it as short. Leave it an inch or 2 long, that will "weaken" the spine, and make for a more stable arrow anyway.

RE: OVER-Spined?
 

Hey guys...

THANKS. THAT is the kind of stuff I need! I appreciate that a lot....all of you.

I want to shoot a really heavy arrow.....well.....because I can. I'm a 20yd max guy, now.

Very informative guys......again, thanks!:)

RE: OVER-Spined?
 

Jeff, the FMJ's I built late last season are 400's and ended up weighing over 500 grains with feather fletch. There are ways to add weight as mobow menrioned above. Another alternative is adustable weight inserts, brass inserts, and heavier heads. All those will also increase your FOC which is also a good thing;)

Dan

RE: OVER-Spined?
 

ONLY constant I know right now, Dan.....is there WILL be a 100gr Rage 2-blade head on my hunting arrow.

ANYTHING else is negotiable. I'll do whatever it takes to get my arrow weight up to where I feel comfortable.

RE: OVER-Spined?
 

The Brass inserts in my FMJ's weigh 100 grains alone add 125 grain Slick Trick to that and you have 225 grains on the end of that arrow for 20+% FOC. If a brick gets in the way no big deal;)

There are adjustable weight inserts for ACC's as well and I have them on my 3-39's. I add just enough to get 12% FOC with my hundred grain Slick Tricks. Those are my speed arrows when I hunt out west.:D

Dan

RE: OVER-Spined?
 

Does a really heavy arrow translate to an over-spined arrow?[&:]:eek:

RE: OVER-Spined?
 

One thing to keep in mind is the spine charts and software to pick a spine is a suggested STARTING point. Two supposedly identicle bows in two different shooters hands could "like" different spined arrows.

As mentioned there are ways to take a big arrow and weaken its spine, any weight you put on the front end will in effect weaken the spine, and any weight you take off the back end will weaken the spine, so:
-heavier insert or BH
- lighter fletch (feathers over vanes for example)

At 20 yds and 300+ fps, you will need it to stablize quickly for max penetration (but keep in mine we could be talking about how hard you have to pull to get that pass through out of the dirt ;))

If you want the bigger/heavier arrow, go with big, thick walled alumns or some of the carbons that are higher gpi. Then leave it 3-4 inches longer than normal and toss in a big head or heavy insert.

If you want to see how stable/unstable it is, do as suggested above, shoot without the fletch on it (for a perfect match, wrap an equal weight of tape around the tail end to get FOC the same). This will show how much work the fletch is doing.

When your form is dead on, the spine being stiff doesn't matter as much, but it does matter a little.

RE: OVER-Spined?
 

No. But rather than spill the rhetoric.....these guys have given me a means to shoot both a heavier arrow AND still be spined correctly.

That is what I was looking for. I just needed to know WHY my logic as flawed. Not that it simply "was".

RE: OVER-Spined?
 

Not at all, For my set up I have properly spined arrows that weigh in a range from 326 grains to 500+ grains. Spine and weight are entirely different beasts.;)

Dan

RE: OVER-Spined?
 

Yes, you can shoot a heavy arrow and still be spined correctly. I didn't know that "being spined correctly" was the question being asked though. I was under the impression that it dealt with being over-spined which is somethng different.

Take a look at a 2020 aluminum, at 29" it weighs 392 grains, deflection .426
Then look at a 2512, at 29" weighs 299, deflection .321 (much stiffer, less weight)

What I am saying is that there is not always a direct correlationin increasing shaft weight and increasing spine.

There are also weight tube options to increase weight.You could alsostiffen the spine (if necessary)and go to muchheavier heads if you are looking to increase total arrow weight.

RE: OVER-Spined?
 

Bob H - it is my understanding that adding weight at either end of an arrow will cause it to flex a little more in the middle. The FOC, however, will increase by adding weight to the front or removing it from the rear.

RE: OVER-Spined?
 

With todays compounds and modern rests, over spine is not as big of a problem as underspine. As for trad bows, its all important.

RE: OVER-Spined?
 

the way I was taught is opposite ends have opposite effects. So think of it this way, put a weight up front and the arrow will take more of a "push" to make it move, hence will flex a bit more then with a lighter front end. This is weaker spine.

Put a heavy weight in the back and again takes more of a push, but the resistance is on the back end hence it flexes less.

It works in my head [8D]and matches what I've read. I have also plugged it into software to pick shafts and it shows the same. though the weight difference in what you can do on the back end is smaller than the front end.