I have this simple question. Why do I always read about poundage questions , but never about real FPE form a given set up? I have a 55# @ 31" Black Widow, and my brother has a 60# @ 28" black widow as well. Both one piece and very similar. Anybody would assume that the 60# bow is more powerful than the 55# bow. Lets just look at the numbers. 60# @ 28" shoots a 517 grains arrow at 160 fps. 55# @ 31" shoots a 560 grains arrow at 175 fps. That is 29.5 fpe for the 60# bow Vs 38 fpe for the 55# bow. A bow approximately 9% heavier shoots some 35% less energy than the 55# bow. The real difference is draw length. Both have a 8.5 inch brace height , however, one have a power stroke 15% longer ( 19.5 vs 22.5 ) with 9% less weight ( 55 vs 60# ). So when someone asks about "is this many pounds good for xxx animal enough?", the question is almost meaningless without the rest of the information. That's why I prefer to hear the question as : would xxx many fpe be enough for xxx animal? Not to mention the weight of the arrow and type/design of the broadhead. Some would argue that this is traditional and that we don't do fps, energy curve , momentum and so on. That it has always worked and we don't care about those things and that there is only one type of death . I disagree since the animal we take does not care what we used to shoot the arrow , and that we should care to make a clean and fast kill. I have seen to many self bows (poorly made , I may add ) go on hunts that were total failures and animals never recovered or just poor penetration to make a fast kill. I have also seen the exact opposite , when a well made selfbow out shot a store bought bow. What are your thoughts on this ?

Well, two things of which I am quite certain are the facts that 1) you are not the first one to bring this up, and 2) you are dead nuts on the principle.

Bowmania killed a B&C Moose with “#38“, (but/and) it was a Supercurve which has an energy output comparable to a fair number of bows in the #50 @28“ range. So was it a #38, or was it a #50? Doesn’t matter. What matters is that the bull died promptly and as expected.

How many pounds you pull is all but meaningless. All that REALLY matters is grains of arrow X feet per second, which is reat about the efficiency of the design. But POUNDAGE (@28”) is what is marked on the bow… and POUNDS are what the Archer must be able to pull.

So if you look at draw weight regulations… A bow which hits the legal minimum at a 23” draw length will never, ever, ever, EVER have the energy output of a comparable bow which hits the same poundage at 28 inches or 30 inches or 31 inches… Fill in the blank. Not gittin’ it Done.

Reality is all about the physics, which can be readily documented by the draw force curve… or with a chronograph and a grain scale, of course… The latter being the preferred method by far.

I have some buddies at the Club who wonder why I think I need to shoot bows which net 52 or 55 or 60 pounds at my DL, and it is really pretty straightforward… They don’t think they need more than 45 pounds, because they draw 29 or 30 inches. I cannot equal their power output without going to higher poundage or spending a small fortune on a fancy Supercurve which (frankly) does not please my eye. So yes, I am a short guy who is trying to compensate for something. The difference is that what I’m trying to compensate for is 100% reality-based. Especially in the event that I get to go home and chase some Elk.

If all I cared about was shooting targets, I suppose there is no penalty for noise or light arrows and I could just drop down to 6 1/2 or 7 GPP and not worry about it. But I am still clinging desperately to the idea that I’m in this for the Hunting.

You wanna hunt, you gotta get the energy/momentum at your striking distance. And of course, it does help to make sure that your arrow is flying straight when it gets there

A test I did a while back

https://leatherwall.bowsite.com/TF/lw/thread2.cfm? threadid=316615&category=88#4761973

Not sure that link work, copied my original post

I ran another test this time using one my frankenbows. In this case a converted Hoyt Stratus compound riser then attached ILF Hoyt short limbs wood/ glass normally 48# on a 25” riser. On this setup the riser is 19” and with limbs screwed all the way down pulls 60# at 28” draw, maximum preload. Using the same 567 grain arrow it averaged 182.0 FPS. Then I backed out the limb bolts ( about 3 3/4 turns) until it drew 60# at 30”. Using same arrow and drawing 30” to the same 60# it shot an average 186.2 FPS. I did not readjust the string so brace height increased 1/8” after backing out the bolts. So now we a test where limb mass is the same and despite not short drawing so the recurves work and increased preload and very slightly decreased brace height the longer draw still out shot the shorter draw by 4.2 FPS

Stroke trumps poundage. Thats what I believe.

I have seen lots of guys that don't reach a full extension. I was one for many years.

The trouble with learning full extension is that you will begin to look like an "aimer" and not like a born natural.

Nobody likes to aimers, its not natural.

Que the music..

Bob! LOL! Here's a great pic of me not aiming at full extension! LOL!

BTW?...I love not aiming!...what do you think my gap is?...LOL!

Savage, very true, most of us when checking draw length do it differently than how we actually shoot.

Many stores use a youth bow and the person stands erect, Olympic style. Then when actually shooting they lean forward and can’t the bow. Losing 2” of draw

It’s a strange male ego thing. Many draw less than they think. And many seldom get to the anchor they measure from.

For example when I shoot through my Chrono. I used to hunch over to make sure I shot the correct spot and I found that I lost another half inch of draw when shooting through the Chrono

when I position the Chrono to stand up fully, Olympic style and extend, I get much more speed.

Try this test. Tell someone you’re going to check their draw length. Most will stand, draw and anchor differently from how they shoot

The most interesting number to me is the fps. developed per inch of draw length.

That number should rema8n pretty consistent over a range of draw lengths. But, there will come a point where the increase in draw length begins to produce fewer feet per second per inch. That's where the efficiency of the bow begins to decrease.

If I can see my "string blurr"?...I'm not at full extension...which is why a lot of folks loose their string into their lips and nose...it's what their string hand forearm was aimed at.

The things not measured in anyone’s equation are the biggest factors in taking game. Sharpness of broadhead, good arrow flight and hitting the right spot - if you don’t have those three checked off FPS, FPE, etc. don’t mean much.

Preach it HRhodes! LOL! :)

Those broadhead , arrow flight and hitting the right spot issues are considered a given to begin with, hence ,they were never mentioned. This was only to compare the actual power generated by a bow based on poundage and draw length .

But those are never a "given" as can be attested to by the stories we see and hear every year from guys who even struggle to hit a soccer ball size target at twenty yards or less. Most of us have had a struggle or two in our bowhunting lives, but most should know by now what it takes to kill game. Diving into numbers is pretty much meaningless in a brick fight.

See Nemo’s post in the “Bow Energy “ thread. Papa Bear had it figured right decades ago.

A whole lot of shooters WILL miss that 'soccer ball at 20' first shot, based on what I've seen at the range. Some won't hit it regularly first shot at fifteen either. Ten is WAY more likely. Guys that can really hit first shot are few and far between.

Marginal accuracy is the norm for most shooters shooting off hand, and that includes all hand held weapons not just stickbows. That's just a simple statement of fact. I've shot possibly a hundred thousand rounds at the range in my lifetime and only remember a few guys that were 'good shots' off hand. Bench resting and sniping excluded. That's not physical.

since when was this thread about hitting anything at any range? this was solely about what power you get from a bow at different draw lengths and poundage.Not about how many thousands of round you or anybody shot at any range or benchrest or anything like that. But since you went that way, think of it as the comparison between handgun cartridges from handguns vs same round from a lever action rifle.When you hear such comparison , no one ever talks about how god or bad of a shot anybody is or what bullet design is more efficient at stopping your threat or point of impact.

"But those are never a "given" as can be attested to by the stories we see and hear every year from guys who even struggle to hit a soccer ball size target at twenty yards or less."

That's my reply. Why do you care is my response to you. "this was solely about what power you get from a bow at different draw lengths and poundage."

That's true, but topics get sidetracked all the time. I frequently go off topic, and generally preface when I do so if way off topic.

"But since you went that way, think of it as the comparison between handgun cartridges from handguns vs same round from a lever action rifle.When you hear such comparison , no one ever talks about how god or bad of a shot anybody is or what bullet design is more efficient at stopping your threat or point of impact."

haha

I lost some draw length when I started anchoring the arrow below the pupil of my eye. Before that, I anchored back at the corner of mouth and I was having left-right problems. Canting the bow to bring the arrow into my line of sight was too "hit and miss" for me.

I tried to anchor like the pic of jinkster. First shot sent my glasses down range and just about ripped my ear off. No thanks. I’ll keep my shorter draw.

“ Canting the bow to bring the arrow into my line of sight was too ‘hit and miss’ for me.

Sounds to me as though you were counting the bow but not your head. My preferred anchor is at 5 o’clock to my eyeball, so I have to tip the crown of my head to 1 o’clock in order to move the anchor down to six. Try it in front of a mirror, and you will see what I mean.

I feel Doc’s Pain……

I have some very “expensive“ frames, but they have been shot clean off my head probably four or five times and are still kicking, so when you factor in the hazard pay, they are actually the most cost-effective option I’ve come up with. I’m on my second pair of frames in the last 25 years (and they are still DAMN stylish!). It’s also nice that the frames weigh about 2 1/2 or 3 g, because Titanium…

But now that I need bifocals/trifocals, I just put in my distance-only contacts when I’m going to go shoot.

I have tris but don't wear glasses when I shoot. Fortunately my distance vision just isn't that bad. Plus it gives me an excuse for being a mediocre shot. haha

Speaking of glasses, anybody that needs them to shoot, should consider a pair that doesn't have progressive lenses. Discuss being an archer with your doc before ordering. I bought into the 'Get progressives!' crap one time. Head cocked to side at full draw I couldn't see squat looking out the side of the lens.

And WAY off topic, plastic lenses SUUUUCCCK! I hate them. They scratch the day you buy them. If you're a tradesman that wipes them off on the inside of your shirt, like you do glass lens, they are rendered worthless in one month. Far as I'm concerned they are a total con job on the public. And don't get the 'anti glare' coating either, as it scratches too.

Ok off rant. Carry on. lol

The only thing I can think of (relevant to the OP) to add to this is:

Lowering your brace height to gain power stroke is counter productive, and will reduce arrow speed, "unless" the bow was set at to high of a brace height to begin with.

Your draw is your draw, and if the brace height, and other tuning aspects are correct/good, then you are getting all you can get.

Rick

"Hank Thoreau" did some nicely documented work on this topic, with pretty careful measurements over long distances of draw, etc. Really well done testing from a guy that made his living doing this sort of stuff in past. In short:

FPS of arrows on his test went up ~8FPS for every inch of draw Energy increase was phenomenal - for example, going from 28" to my 31.5" added almost 20% more speed and 40% more energy.

Lighter bows, drawn a long way, can be deadly powerful. Especially the "supercurves"- my light draw supercurves at 31.5" are very, very fast.

If interested, I roughed out a simple formula for this as follows: Start by treating your bow as a perfect sphere... :)

Hanks work at link below: https://www.archerytalk.com/threads/affects-of-draw-length-and-arrow-weight-on-speed-and-efficiency-border- xp10.2401673/#post-1072120881

I've said this for years. Asking "is XX lbs. enough" without considering draw length is nearly pointless. And yet...

The easiest way to know is something is enough. Is to get out there and kill some critters.

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