IBO & AMO

[WThunter]

What does IBO and AMO stand for?

[PABowhntr]

IBO is International Bowhunters Organization

AMO is Archery Manufacturers Association and I believe it has now been changed to Archery Trade Association (ATA).

In terms of arrow speed it is usually considered as a test standard with specific criteria.....in other words...

IBO speed means a 70 lb draw weight, 30 inch draw length and a 350 grain arrow. AMO speed means a 60 lb draw weight, 30 inch draw length and a 540 grain arrow.

The AMO method has strict criteria that you need to follow where the IBO is a bit more liberal...

[WThunter]

So, from what I gather the AMO is more likely the range of speed one will get in a hunting setup. Is that right?

[Rangeball]

If your hunting set up is 9 grains per pound out of a 60# bow with a 30" draw...

Your probably safer to guesstimate a little more than half way between IBO and AMO specs for a hunting set up...

[Ossage]

If you compare a bunch of figures, and if you can trust them, you will notice that some bows seem optimized a little moreso than others on ramping up speed for either lighter (IBO) or heavier (AMO) arrows, which is interesting It isn' t just the maximums that vary.

[PABowhntr]

Good point Ossage. It is interesting how two similar bows can have the same AMO speeds and yet vary in IBO speeds by as much as 20 fps.

I tend to agree with Rangeball about what you can expect from any given setup. Most folks who set up their bows and do not really care about speed usually end up with an actual speed closer to the AMO rating for the bow. Those of the archery community that do care about speed tend to do everything possible to their setups to achieve the fastest speed from their bow without compromising accuracy or practical issues such as noise and vibration levels when it comes to a hunting rig. In their cases the actual speed of their bow will normally be at least halfway between the AMO and IBO speed ratings for the bow if not even closer to the IBO speed rating. Rarely, if ever, does someone actually have a setup that will surpass the IBO speed rating for their bow.

[IMN23D]

But...Doesn' t the AMO set the standards for your bolt and thread sizes for things like your sights and rest holes in the bow? Also precise measurements for draw length. The AMO speeds are usually more accurate among bows because the IBO standard can take a bow with a 30" tag on it but it might actually measure 30-3/4" amo. Thats how some of the mfg get away with some of their advertised speeds.