42lb recurve is 500 grains to heavy?

[brokestik]

I can give you an e-mail of the best arrow maker in the world IMO. He's been making them and matching arrows to bows for almost 40 years. [email protected]    E-mail him and he'll be glad to fill you in on the match-ups from a builders point of view.

[Keb]

Thanks for the help, I am a hunter 1st, 3d as practice, I am really only worried about 20 yards and in at this point.

I ordered a set of 5/16, 40/45 spine from the guy who made 11/32, they will be a touch lighter, maybe 40 to 50 grains.

The most important thing I found was the 11/32, 45 to 50 may have been to stiff, and the 40/45 are more accurate for me.

So in the end, I have med weight, smaller diameter, arrow that's more accurate , win win.

[FarmerMarley]

I am curious...And I am a newbie, so I am here to learn from all the experienced folk. But I am curious about the supposed point where too much weight equals less penetration?  

I can see the limitations of arrow weight (GPP) on trajectory and aiming. I also can see how a slower arrow might give an animal more time to jump the string. but it must take a ridiculously heavy/slow/high GPP arrow before penetration would be reduced.

Maybe my understanding of physics is limited. From what I remember: velocity loses its energy twice as fast as momentum.

Thanks for the help guys,

[Friend]

Believe there would be much danger in being hit by a train traveling a mere 7.3 fps(5 mph).

Momentum...Momentum...Momentum

The point of diminishing returns is restricted to an archers manageable trajectory for the hunting range required and/or mastered.

[KyRidgeRunner]

[stujay]

Short answer no. Your results speak for themselves.

[Roughrider]

The assumptions that too heavy of an arrow looses power just aren't proving out in testing. I shot arrows weighing from 450 - 2220 grains (the 2220 grains was a solid fiberglass rod from a blind)through four bows ranging in weight from 41 - 64 # - all drawn to 28"  

Both momentum and KE kept increasing.  In fact, a 740 grain arrow (137fps) from the 41 pound bow has more energy than the 450 gr arrow (204fps)from the 64 # bow.  The 2220 gr arrow had almost twice the energy of the 740 gr. arrow from the 64 pound bow.

The really interesting thing in the preliminary testing, is that all of the bows lost about 100 fps from the 450 - 2220 grain arrows.  

Look at it this way - if you could make and arrow that weighed 1/2grain, it would leave the bow at whatever speed the string is travelling in a "dry fire" situation - maybe 400 fps, but it would only go a few feet and have no energy - imagine a whiffle ball.  Now, a bow could "launch" any arrow lighter than the bow's draw weight (a 40# arrow from a 45# bow) - granted perhaps not very fast and not very far, but it would probably penetrate pretty well.  There probably is a scentific formula for this all, and there well may be a point of diminishing return for power only, but I would think it would be in arrows weighing pounds, not grains.

Power isn't the only consideration, you do have to be able to actually shoot the arrow, but I've noticed little difference in my ability to shoot accurately whether my arrows weighed 450 grains or 750 grains - and yes, I can shoot further than 20 yards.

I'll do more complete, careful, and detailed, testing and post some results on a new thread in the next days.

[FarmerMarley]

Sounds like a very interesting experiment Dan. I looks forward to reading about it. High GPP arrows is one of the things I am very interested in right now.

[Roughrider]

I did run further tests today and verifed the preliminary results.  

I made up ten arrows with weights of 390 - 2220 grains and shot them from four bows of 41 - 64 pounds, all drawn to 28" and all hand shot, finger release.  The bows were two r/d longbows and two recurves.

All bows increased both momentum and kinetic energy as the arrow weight increased.  One of the most interesting things was that across all four bows, the total speed lost going from 390 - 2220 grains was very close to 100fps.  

Also, all the bows lost about 15 fps going from 450 - 550 grains, but only an average of 6 fps going from 850 - 950 grain arrows.  The 740 grain arrow produced almost as much foot pounds of momentum out of the 41 pound bow as the 610 grain arrow out of the 64 pound bow.  

Depending on the bow, the 42 pound recurve with 500 grain arrow questioned in the beginning of the post would have a speed about 170 - 175 fps.  which would produce about 12.3 fp of momentum.  

Every 100 grains of arrow weight increase would reduce speed by about 12 fps, and increase momentum by about 1.2 pounds.

[Bobaru]

I'm pretty much with AWPForester.

In my opinion, one has to be cautious with the mental application of theory alone.  I have read all these posts for about 2 years now.  But, at the end of the day, only one's own tests matter.  And, even then there is lots of room for differences.

I sure wouldn't want to be hit by a 5 mph train. I also wouldn't want to be hit by a 7 mph train that had 70 cars instead of 100 cars.

I have a 58# bow that I switched to carbon two years ago.  I worked up arrows that penetrate as well at 7 GPP as the other arrows at 10 GPP.  I don't know why, but they do.  I tested them.  And, I like the way they shoot, they're proven effective.

I went out and got a 48# Blacktail and, again, carbon arrows.  They worked up to about 9.5 GPP to get them tuned properly.  I like them.  They work well for me.  I like the way they fly and penetrate.  

As with the 7 GPP, I was really worried about effectiveness because the conventional wisdom is that they won't penetrate.  So, I did controlled tests.  And, I don't know about the physics, but, the tests showed they penetrated as well as the heavier arrows.  

I don't recommend 7 GPP arrows.  I do recommend testing to make sure what you're taking out to hunt is ethical in terms of being an effective killing instrument. That's a personal respondsibility that goes beyond theory, in my opinion.