Heavy bows/ trajectory

[Orion]

Laker:  I dunno.  I think you should be able to indulge your desires without breaking the cookie jar by going to used bows. There are a lot of good used bows out there in weights over 60#, though admittedly, they are a little more scarce above 70#, but because of their weight, they are more difficult to sell and usually priced very reasonable. I think a bow wanted ad would bring a lot of responses. Good luck. 

[pavan]

Out of curiosity concerning this heavy bow stuff, I weighed my heavy bows cedar arrows that I still have that are 27" bop with 160 grain head and are 80 to 100 pounds spine.  They weigh from 590 grains with 160 points to 648 with 160 grain points.  I was a long ways from ten grains per pound shooting the 80 to 96 pound at my draw bows.  I only used B50 strings on them, yep, those heavy longbows had a little thump.  That would also explain the over 70 yard point on. 

[YosemiteSam]

Some folks like heavy draw weights for their own sake.  I've heard that it helps compensate for a less than ideal release.  Some folks use draw weight as a proxy measurement for what they really like, which is actually just speed/arrow performance.

If you're more in the first camp, then you can probably find a heavy-weight (albeit lower efficiency) bow for not much money.  An 80# basic longbow or flatbow, perhaps?  If you lean more toward the second camp, consider spending a little more on a higher-performance bow at the same weight you have now or even less.  There, you get a little extra speed for little to no extra weight.

And if you just want penetration, then consider going up in arrow weight but forgetting about the speed cost.  10 gpp is a good rule of thumb but 13+ is still perfectly reasonable to me.  One of my favorite hunting authors, David Petersen, shoots around 13.5 gpp, I think.  He uses narrow single-bevels, heavy arrows and short bows to take elk within a max range of 20 yards.  At 72#, that puts you at a 972 grain arrow.  I'm sure it's a dog of a trajectory at 40+ yards but it probably won't stop at anything except a tree or the ground.

Just some stuff to think about.

[Lakerat007]

Some folks like heavy draw weights for their own sake.  I've heard that it helps compensate for a less than ideal release.  Some folks use draw weight as a proxy measurement for what they really like, which is actually just speed/arrow performance.

If you're more in the first camp, then you can probably find a heavy-weight (albeit lower efficiency) bow for not much money.  An 80# basic longbow or flatbow, perhaps?  If you lean more toward the second camp, consider spending a little more on a higher-performance bow at the same weight you have now or even less.  There, you get a little extra speed for little to no extra weight.

And if you just want penetration, then consider going up in arrow weight but forgetting about the speed cost.  10 gpp is a good rule of thumb but 13+ is still perfectly reasonable to me.  One of my favorite hunting authors, David Petersen, shoots around 13.5 gpp, I think.  He uses narrow single-bevels, heavy arrows and short bows to take elk within a max range of 20 yards.  At 72#, that puts you at a 972 grain arrow.  I'm sure it's a dog of a trajectory at 40+ yards but it probably won't stop at anything except a tree or the ground.

Just some stuff to think about.

Agree, a 70# bow sure comes off the fingers a lot easier than a 45#. Though when I started with a light bow I never had issues but if I pick one up now I just can't get my hand off the string without forcing it.  I said I like to shoot heavy arrows fast, but I was just refering to avg speeds opposed to overloading a lighter bow casting rainbows. Guessing I send 730 gr in mid to low 170s fps which I'm fine with. The thing about the used bows I come across is they can only handle B50 and I just can't get used to all that stretch. My arrow set up is prob diff than most lol. I get the lightest carbon I can get my hands on, in a .300 spine and cut it off as short as I can. Then I bareshaft and start front loading the heck out of it, and keep loading until it starts looking weak. I really like this set up other then the bow is junk but after hearing everyone's opinion I'm content in the low 70s

[Terry Green]

Bisch.... new format and stupid cell phone I guess...
 I'm still learning myself...

[Hermon]

I'm trying to handle this delicately as possible I don't want to get broadside again..... but I'd like to know since the upper 50s let's say 57 lb shooting  10 grains per pound so that would be a 570 grain Arrow let's say running at 180 feet per second ......

and now let's take a 70 lb bow and a 700 Grain Arrow running 180...

 Could someone please explain to me how there's NO net gain?

Reading this thread jarred my memory about an article I read many years ago.  Now I am not saying that this theory is correct, just what the author stated.  (And I wish I could find it so that I could quote it better) 

The author said that that there was a diminishing gain in the bows he tested (at what point I do not recall) where to get more draw weight the limbs had to be thicker/wider/heavier.  This made the limbs slower to recover compared to the lighter limbs.  So a 50# bow with a 500 grain arrow might shoot 180 fps, but a 75# bow with a 750 grain arrow may not shoot 180 fps.  If the heavier bow shot slower, he thought that he had reached the point of diminishing returns.   Don't know if he is correct or not.  Seems it would take several bows of the same design (ideally same form) in several different draw weights matched with arrows at the same gpp of each draw weight.   

IMO, shoot as much bow as you can accurately.

[Terry Green]

 Okay so what if the 75 lb bow shot a 700 grain Arrow at 180 can you run the numbers on that versus the 57 pound bow?..... can you tell me after running the numbers which Bow wins?????

[Hermon]

Not disagreeing Terry.

[Longtoke]

Would be interesting to see some test results of people comparing the same models but in different weights.  surely someone has data like that.

[LBR]

I shot 82# for years.  I've pulled over 125#, and did a lot of shooting with a 98@28 (around 120# at my draw).  I won a lot of tournaments shooting that 82# bow.  Looking back, I would have won a lot more if I'd dropped down in poundage some and I figure my joints would be in better shape.  As for killing things...first buck I shot was with a 66# bow.  Arrow buried up in the dirt almost 8" after it passed through the deer.  The deer didn't ask me how far that arrow went in the dirt , it just died.  Even shooting lighter bows can cause wear and tear on your joints.  Although I can still pull heavy, I've dropped back a lot because I want my joints to last longer.  My shooting sessions also last longer, my fingers don't get sore, and I'm more accurate.  If I ever get a chance to hunt something bigger than a whitetail again, I'll shoot heavier for a while until the hunt is over, then I'll drop back to around 55#.

[pdk25]

So many factors go into answering the original question.  It is different for everyone.  If I had no plans to hunt big dangerous game overseas and could only use one bow, it would be one that is in the upper 50#'s at my drawlength, which is between 29.25 and 29.75" depending on the grip.  The long draw gives me some extra energy that someone with a shorter drawlength doesn't get, so let's me get away with a relatively lighter bow and still good performance.  This should be enough comfortably to account for stand hunting in cold weather with lots of garments on.  It also helps to account for getting some minor injury, sickness, muscle fatique, etc..., not to mention longterm decreases in strenth.

With that being said. the hog I shot last week was shot with a bow that is around 65# at my draw length, and since I shot my turkey with a recurve that is 57# at my draw length, I have only been shooting 2 bows.  One is 65# and the other was set at 76# at my drawlength.  I just tightened the bolts to bring that one up to 81-82#, and have a bow on the way that should be a  little over 86# at my drawlength.  That will probably seem a little stiff until I get accustomed to it.  The only reason that I am shooting the heavier weights is to make the lighter bows easier, to maintain strength, and to be ready in case I get a chance to chase Buffalo again.

Terry, I am not sure what was meant by no gain, unless they were referring to the animal already being dead.  The argument of diminishing returns is a poor one that has never been quantified.  If you only got 90 percent (or even 80%)  performance gain per pound for a similar bow over 70 pounds compared to  bow in the 50# range, that would be substantial.

[Recurve7]

Clay,
Welcome to the world of traditional archery. I applaud you for being able to shoot the weight you mentioned. However, there comes a place where you get very little gain for the energy spent. It's like loading magnum ammunition. I can take a 30-06 180gr bullet, with about 60 grains of powder and get close to 3,000fps. Put the same bullet in a 30-378 case with a 114grs of powder and get just over 3,200fps. I've almost doubled the powder charge, for about an 6% increase in velocity. I suspect your getting close to that " efficiency " with the heavy draw weight. I also suspect, no matter how well you can shoot 75#, you can probably shoot 65 better. Especially, in a hunting environment where temps and clothing becomes a factor. And, it's a lot of wear and tear on you that may surface later on.
But, I understand where you coming from. I ordered my first custom bow in 1994 from Bob Lee, I was shooting 70# compounds like they were nothing. It took lots of persuading from Bob to talk me down to 63#. After all, I was humiliated by the thoughts of a 65# bow. I know now Bob was right. My last custom bow was ordered at a mere 52#. 
Nevertheless, welcome and good luck with what ever bow you choose.
Mike

[Lakerat007]

Clay,
Welcome to the world of traditional archery. I applaud you for being able to shoot the weight you mentioned. However, there comes a place where you get very little gain for the energy spent. It's like loading magnum ammunition. I can take a 30-06 180gr bullet, with about 60 grains of powder and get close to 3,000fps. Put the same bullet in a 30-378 case with a 114grs of powder and get just over 3,200fps. I've almost doubled the powder charge, for about an 6% increase in velocity. I suspect your getting close to that " efficiency " with the heavy draw weight. I also suspect, no matter how well you can shoot 75#, you can probably shoot 65 better. Especially, in a hunting environment where temps and clothing becomes a factor. And, it's a lot of wear and tear on you that may surface later on.
But, I understand where you coming from. I ordered my first custom bow in 1994 from Bob Lee, I was shooting 70# compounds like they were nothing. It took lots of persuading from Bob to talk me down to 63#. After all, I was humiliated by the thoughts of a 65# bow. I know now Bob was right. My last custom bow was ordered at a mere 52#. 
Nevertheless, welcome and good luck with what ever bow you choose.
Mike

Mike,
Thanks! That explanation was what I was looking for. While I still see benefits to going heavy if one can handle it I was trying to figure out when the benefits start to peter out. Also wanted to hear from someone who has been there done that and the effects it has on the body. I never wanted to go heavy just so I can say I shoot a heavy bow. Think the good lord gives us  all diff gifts, yes I was blessed with the natural ability to handle a lot of weight but I'm also dang near blind in my dominant eye. Funny how that works sometimes. Thanks again and a thank you to everyone else for there input.

Clay

[monterey]

Would be interesting to see some test results of people comparing the same models but in different weights.  surely someone has data like that.

A useful comparison would require that the bows being compared be identical in every respect except the thickness of the limbs.  Same form, same materials, same width same profiles.  Everything except the thickness of the limbs.  The heavier bow is going to have thicker limbs in order to achieve the weight.

My own guess is that there would not be a point of diminishing returns as far as speed goes.  I think there would be a small but measurable increase in speed.

[Sam McMichael]

Lots of interesting things have been mentioned, but it still comes down to preference, what performs best for a given hunter. I can't shoot the heavy bows any longer, but if I could, I would still be hunting with that 78 pounder. I totally agree with Terry that a two arrows traveling at the same speed are not equal if one is significantly heavier than the other, as the extra weight translates into penetration.

[Terry Green]

Again... take your 57 pound bow to Africa along with a friend who has a 90 bow to Africa and both of you shoot a broadside cape buffalo at the same time and see who has diminishing returns.

[pdk25]

And really, as I have said before many times.  There has been no quantification of the degree of diminishing returns, and examples as with the rifle above greatly overestimate any diminishing returns that are present.  I see it mostly in arguments against shooting heavier, more energetic  setups.  Anyone who knows me knows that I don't care what anyone else shoots, and whatever you choose to shoot, adequate accuracy under hunting conditions is paramount.  I just don't like misinformation being diseminated.

[pavan]

I had heavy bows and heavy arrows way back.  I stuffed Microflites.  I wanted to shoot a moose, but when I had a chance to shoot a moose, it all came to easy and I couldn't do it.  Moose and Iowa whitetails are not the same.   Since then, I have crossed paths with a number of moose on canoe trips and have no desire to hunt them.  I did shoot a domestic buffalo with the heavy arrows, He was a nasty bull that they could never handle, it got crazy when they tried to coral him with the rest of the herd.  He broke through fences and got into the corn fields.  I got the arrow sticking about 20" out the other side, I was expecting a pass through. 

[Terry Green]

Okay so what if the 75 lb bow shot a 700 grain Arrow at 180 can you run the numbers on that versus the 57 pound bow?..... can you tell me after running the numbers which Bow wins?????

[LBR]

The situation determines if it matters.  If you are hunting a Cape Buffalo, you definitely want to shoot a heavy setup...most of us won't get to hunt game like that though.  Speaking with Dr. Ed Ashby some years ago, he assured me that my [email protected] longbow would be plenty with the right arrow.  Unfortunately I never got to test it.

If you are hunting whitetails, as I noted before the deer couldn't care less how far the arrow buries into the ground after it passes through the lungs.  If you shoot a lot over a period of several years;  and/or have other injuries (i.e., torn rotator), your joints will care.  You can shoot longer sessions more comfortably, if that matters, with less weight.  That's a lesson I learned the first time I shot a field round with 82# in 90+ degrees.