You are correct but I think the point is more visible with the greater disparities.
You are correct but I think the point is more visible with the greater disparities.
WillBates
Member
It is generally believed that an arrow with a high FOC will fly well, but with premature loss of trajectory (nose-diving). While an arrow with a very low FOC will hold its trajectory better, but it will fly erratically. So again, another trade-off for you to consider. My deer crossing hunters, 8.9 gpi, 27.5 inches, 50 grain 3rivers brass inserts, and a 125 grain head with penetrate 8 inches farther into my spiderweb target than my CX maximas. Supposedly better foc tunes better, flys better/less windrift, but will drop more do to extra weight. Back to the topic, heavier arrows are less affected by wind and carry energy better at longer ranges. Your bow is more efficent with heavier arrows. If you want some better info look into Dr. Ashbys tests of heavy arrows and extreme foc. Pretty cool info.
With light arrows, alot of companys and people are making high foc setups. Victory started this by introducing the vaps. Lighter arrow with heavy foc=high penetration. May not have as much energy as a heavy arrow but with high foc its a wash.
http://www.alaskabowhunting.com/Dr.-Ed-Ashby-W26.aspx
Also if anybody does a higher foc arrow, like myself, make sure you spine up because adding that much weight will weaken the shafts considerably.
Another cool thing to have for testing foc, momentum, spine, and ke is the Ontarget spine selector software.
With light arrows, alot of companys and people are making high foc setups. Victory started this by introducing the vaps. Lighter arrow with heavy foc=high penetration. May not have as much energy as a heavy arrow but with high foc its a wash.
http://www.alaskabowhunting.com/Dr.-Ed-Ashby-W26.aspx
Also if anybody does a higher foc arrow, like myself, make sure you spine up because adding that much weight will weaken the shafts considerably.
Another cool thing to have for testing foc, momentum, spine, and ke is the Ontarget spine selector software.
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HuntNFish
Member
Compelling argument - your figures are correct, but lets figure this back to archery the power in those loads would represent the bow so you have a ton more powder in the 375 H&H, if you were to use the same powder (bow) result would be different right? You would see way less energy in the 270 grain bullet than the normal load, thus same bow could never match those figures.
Here's where it goes wrong look at the ratios of the weight and speeds: weigh of the rounds 375 H&H (270 grains) 70% heavier than the 7 RUM (160 grains) and speed only 12% slower 2950 Vs 2600. so that would be like comparing:
350 grain arrow at 320 FPS Vs. 595 grain arrow at 281 FPS, or my Monster Chill R Vs. well I don't know of a bow that can deliver those numbers. No apples to apples here...
Who wouldn't choose the 7RUM on whitetails at an ethical rifle range over the 375 H&H. I believe most would lean hard on the 7MM, again unless you are shooting through brush, wind, rain, etc.
JNRBRONC
Well-Known Member
"Brush busting" rifles/bullets have been refuted. You maybe had me before you went there.
http://archerycalculator.com/archery-kinetic-energy-and-momentum-calculator/
That 595 grain arrow at 281 fps (I'll take that!)
Yields 104 foot lbs of energy and the 350 grain arrow at 320 fps gives 74 foot lbs of energy.
That 350 grain arrow would have to move at 365 fps to match the KE of the heavier arrow.
Not only will the lighter, faster arrow get pushed around more by the wind, it sheds energy a lot quicker.
Even an arrow at 425 grains moving at 290 fps gives 79 foot lbs of energy. I'll take a heavier arrow every time.
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HuntNFish
Member
Guess we will have to agree to disagree, but I will take my much flatter shooting 350 grain arrow at 330 FPS 84.5 ft./lbs KE over your 79 ft. / lbs KE. - get there straighter, faster and hit harder.
HuntNFish
Member
Sarcasm, much like shooting arrows through concrete...
Monsterbuck
Active Member
I think his point is that your numbers are wrong. Shooting out of the same bow (using the calculator you posted) a bow that shoots a 350 gr arrow 320 fps would shoot a 595 gr arrow 238 fps. That calculates to a little over 74 ft KE. Pretty much the same KE as the light arrow.
Actually your number was incorrect. I punched in 350 @ 320 fps on your calculator and got over 79 ft KE so the lighter arrow has more KE.
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WillBates
Member
Even at 82 lbs thats got to be the fastest bow I have ever heard of. Is that speed verified through a chrono or different chronos?
Good god, my Bowtech experience, custom stringed and tuned by Mike Carter aka Crackers, was a factory 335 ibo. After his tuning he got it to ibo at 30in draw 70lbs ect ect up to 350 fps. At my draw length, 28.5 at 70 lb, with a 390 grain maxima shot 323 fps. I thought that was fast. Faster than 99 percent of most peoples setups around here. He even got my buddies experience tuned up to 324-325 with the same maximas. Always said the only thing that would beat it would be a omen or monster.
WillBates
Member
Foc arrows arent a type of arrow. Its just a way to improve arrow penetration and flight. Every arrow has a foc percentage. Look up the foc equation to see what foc your arrows have. Arrows with good foc also recover MUCH faster from the bending or flexing that archers paradox refers to compared to arrows with average to poor foc. Accuracy with my high foc is fantastic. All depends on the shooters ability.
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You are right. It does yield 79 ft lbs. KE.
I'm not sure how I came up with those first numbers (I ran it more than once to be sure).
Despite the fact that the faster bow offers an additional 5ft lbs of KE it does not change the fact that lighter arrows lose speed more and don't hit as hard down range as heavy arrows. Look at the numbers for the arrow weighing 425 grains at 290 fps (a much more attainable set up than 595 @ 281). That arrow will hold that KE longer than one that weighs 350 grains.
By my understanding, the heavier arrow would have a greater chance of pass through at longer distances.
WillBates
Member
Thats a sweet rig. Im sure the whitetails dont realize that they have even been hit with that thing lol
Monsterbuck
Active Member
I imagine the purchased software has it but I thought one of the free online calculators had a function to calculate KE at various distances. I don't recall what the site was.
I think you're right a out a lighter arrow losing speed and KE faster and at some point in the example above the 5 ft/lb of KE advantage the lighter arrow has will reverse. I just don't know at what distance that is.
Honestly with most of today's bows out to 40 yards the arrow speed is such that either light or heavy they should pass through if you don't hit bone.
I shoot a 415 gr arrow. I guess I consider that an in between weight. Not a light weight speed arrow and not a heavy arrow.
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HuntNFish
Member
Crazy fast, that set-up is crazy fast... finally a bow that could come close to shooting to 40 on one pin... sounds like you got another ten grains or so to shave off that arrow. Speed kills... none believers in speed compare this set-up, or better yet shoot one of these (outside at various distances even close) and you will be changed forever... And for those that cant draw 82 turn it down to 60 shave off 120 grains and let her eat..
That's pretty close to what I shoot too. Its balancing act, trying to find the best of both worlds.