got a new bow with the draw weight listed at 47#. Placed it on a reliable scale and it only pulls 44#. does anyone know what is the accepted weight tolerance in the bowyer business?? Should I be returning the bow or is it common for weight to vary from that listed on the bow?
usually about 2-3 pounds
Weight will vary with brace height.
Don, How much can brace height change draw weight? Do I increase ( or decrease ) brace height to increase the draw weight?? Thanks for the help.
I might also note that not all scales weigh the same. Unless the brace height is extremely low now, raising it won't change the draw weight more than a pound.
Both Drew and Don are correct. Plus, how both you and the bowyer measure the draw weight with different scales, different string attachments to simulate fingers pulling, different measurement of the point of measure, and of course the difference in brace height mentioned by Don, will all affect the weight reading. To expand on each of these, your "reliable scale" may not be as accurate as you think. On the other hand, the bowyer's scale may not be as accurate as he thinks. A couple of pounds difference is not that much to be off either way, and both scales may be slightly off in different directions. You probably simply hooked the scale directly to the string and pulled until you got to the length of draw where you made your weight measurement. Some bowyers do the same thing. But others use a device that is much wider in order to simulate 3 fingers on the string rather than just the hook. That kind of device results in more limb flex at the same length of draw, thus upping the poundage slightly. Also, the way you measured the draw length may have been slightly different than the way the bowyer did. I have forgotten the precise criteria for the measurement, but I do recall it is not as straightforward as measuring from the back of the riser shelf. I believe it is done by adding a certain length to the measurement at the deepest part of the grip on the belly side of the riser and then measuring the draw length from that calculated point. An increase in brace height will also preload the limbs somewhat and cause the draw weight at a particular length to change. You could always contact the bowyer and ask him what procedure he uses to measure draw weight and then do your best to duplicate that procedure. Even then, a few bowyers may "cheat" a little and "adjust" the draw weight to meet the specs chosen by the customer.
The problem with an under-weight bow is that you can't add pounds back on. Your bow is definitely in a more marginal weight class for some animals. Bows of that weight (44#) can definitely kill elk and other animals of the same size, but I certainly would prefer the bow to be 47# if I were hunting something larger than animals in the 200 pound range like a large whitetail. I mostly hunt with bows that exceed 50#, and that is the minimum for elk in some states, as you probably know. I usually try to set a minimum draw weight when I order a bow and ask that the bowyer err on the high side by a few pounds if he cannot hit weight. I don't tend to notice an extra 3 pounds and in the field when I am bundled up and in an awkward position, I may not get a full draw and full weight anyway, so a little extra may not be a bad thing. On the other hand, the older I get, the harder it becomes to draw higher weights, so I tend to use lighter draw weights over time. You may eventually be glad that your bow is a little lighter than you thought it would be. A draw weight of 44# is great for most of the hunting most of us do and is a commonly requested draw weight by people having custom bows built for them. I have several bows in that draw weight range, and they shoot very well. I would not hesitate to hunt deer with them, and hope to use them to continue to hunt well into my old age. ;)
Allan
10 point, I've seen an increase of 1" in brace height raise the draw weight by a few pounds, but it depends on the bow's length and design. It was common for Dan Quillian's Bamboo Longhunters to actually weight a few pounds lighter than marked, because the bowyer (Jeffery) checked them with a dacron string at 7" brace height and Dan used FF at 6". And like Allan said, there are several other factors that can cause apparent differences.
Personally I wouldn't worry about 44 vs. 47 relative to killing power. I doubt the animals would notice the difference.
There is an excellent thread just a couple down from this one started by "Buck Hunter" that explains the archery standard for draw length measurement.
Most of my 8 recurves measure 1-4 pounds different (usually lighter) than marked on the bow.
Amar11...Thanks for the tip about using a 3-fingers-wide hook on the scale! I use an Easton Digital scale to measure draw weights which is much better than my spring scale. However I simply use the tiny hook that is attached to it. Your tip makes sense too simulate how a fingers shooter would impact the bow when drawing. I'm not quite sure hot to create such a hook between my scale and the string though?