Draw weight inaccurate?

urnotdone · September 27, 2015, 07:36:00 PM

Hi guys! Just switched from cables and pulleys to a Martin Hunter #50. I draw 30 inches. I wanted to confirm my actual draw weight and invested in a bow scale. After calibrating it against a know 30lb weight, I was surprised to see that I draw barely 50lb at 30 inches. I let my son who draws 28 inches try it and it was about 45lb. Is it common to have the claimed draw weight at 28 inches out by 5lbs?

ChuckC · September 27, 2015, 07:39:00 PM

I don't think it is common for it to be under, but more common for it to be over. Does the weight on the bow show numbers with "X"s in front of it ?

Note too, calibrating it (scale) at one point means it is accurate at that point and not really at any other point. You normally need at least two points that bracket the approximate weight expected.
ChuckC

**DONOTDELETE** · September 27, 2015, 07:48:00 PM

Check with Martin Archery they may very well measure their weight at 30" draw.... or is it marked 30@28?

are you measuring your draw length like this?

urnotdone · September 27, 2015, 08:36:00 PM

Yes, it is marked 50# @ 28"and I did measure draw length like in the illustration. Repeatedly, I must say. To the amusement of my boys!
I will recheck the accuracy of the scale with other weights too.

September 27, 2015, 08:39:00 PM

Not common, but does happen. Like stated above, there is more than one way to measure DL, and that can skew things too.

Bisch

Terry Lightle · September 27, 2015, 09:11:00 PM

Will not call names but a few months back I pulled te easiest drawing 50# recurve I have ever seen,put it on a scale and it showed 39#.Checked 3 other bows and all were within 1 # of markings with the same scale.
Terry

urnotdone · September 27, 2015, 09:30:00 PM

I rechecked the scale with another reference weight and it is surprisingly accurate. Then went and marked an arrow at 28" and drew to that mark. Scale says 41# at 28"! Whow! Didn't think it will be out by almost 10#. Maybe something to keep in mind for guys who think about buying a 40 or 45# bow for hunting. You may have an illegal draw weight for your part of the woods.

CoachBGriff · September 27, 2015, 09:35:00 PM

I have a production recurve that missed the specified draw weight by about 5 lbs. My limbs were heavier than stated though.

It happens. Mine was a 3-piece, so the company swapped out the limbs for me.

newhouse114 · September 27, 2015, 10:05:00 PM

I have a set of 45 lb limbs for my Samick Sage, draws 57 lbs at 29.5"

Sirius Black · September 28, 2015, 06:31:00 PM

I've had too many bows that were under marked. I know this stuff can be a pain.

Mike Mecredy · September 28, 2015, 06:45:00 PM

Maybe it was 50# @ 28" on their scale.

Stump73 · September 29, 2015, 01:23:00 PM

Could be difference between scales?

Stump73 · September 29, 2015, 01:24:00 PM

Could be difference between scales?

lablover · September 29, 2015, 01:47:00 PM

How old is the bow?

MEsquivel · September 29, 2015, 05:07:00 PM

Is your 30" draw length from a compound?

It drops about 1.5-2" when you switch to longbow, depending on your anchor.

fishone · September 29, 2015, 06:12:00 PM

It has been my experience that most bows scale higher than marked on my digital bow scale by a couple of pounds. I have seen a few scale quite a bit higher than marked. I don't I have seen any bows scale under the poundage marked.

David Mitchell · September 29, 2015, 07:34:00 PM

I've had them as much as 4-7# over marked weight. More then one or two!

McDave · September 29, 2015, 08:23:00 PM

Plus or minus 2# is a normal variance for all the bowyers I have dealt with over the years. I can't imagine that a custom bowyer would send out a bow without personally measuring the draw weight, and mostly they get much closer than that.

I would apply the same standard to factory bows, although I don't think they measure every single bow, but if it was off by more than plus or minus 2#, I would return it.

gonefishing600 · September 29, 2015, 08:24:00 PM

If your son is drawing 28" and you scaled him at 45#@28" with a bow thats marked 50@28, then that pretty close. Most bows will gain or lose 3# per inch.

gonefishing600 · September 29, 2015, 08:25:00 PM

QuoteOriginally posted by McDave:
Plus or minus 2# is a normal variance for all the bowyers I have dealt with over the years. I can't imagine that a custom bowyer would send out a bow without personally measuring the draw weight, and mostly they get much closer than that.

I would apply the same standard to factory bows, although I don't think they measure every single bow, but if it was off by more than plus or minus 2#, I would return it.

Martin is not a custom bowyer. They build bows in 5# increment. None the less, I would still return it.