I just purchased a new Bow that was rated at 302 fps and when i put it on the chronograph it only went 218.What is wrong with this and how can I increase my speed.

What is your draw length and what weight is your bow set at?

IBO speeds are generated with a 30" draw set at 70lbs, if I'm not mistaken.

And with a 350 grain arrow with a bare string right?

dctkennels,

Is your bow set up for hunting? IBO speeds are set with a bare bow, basically. NO silencers on the strings, no loop, no peep, etc.... At 70 lb. draw weight and a 30 inch draw, with a 350 gr. arrow.

Shorter draw length, lower draw weight, heavier arrow, and the items most hunting set ups have on the string will all lower your speed through a chrono.

It is typical for all bow set ups to be lower than IBO. That type of set up used to be called AMO speed. I am not sure if that is still the reference name for it or not, but depending on how your bow is set up there might not be anything wrong. If your set up is close to the IBO reference, you may need to have your bow checked again. Also, do not go with the first shot through a chrono. The first shot is often off a bit. Fire several shots and kick out the first and average the rest. That will give you a more true representation. Also, make sure you are shooting through the chrono windows at the right level. High or low will read incorrectly.

God bless

Sounds like two problems. One, you don't know what IBO speeds are based on. Two, unless you're shooting something like a broom handle with a 20 inch draw, your bow is pulling about 35 pounds.[8D]

My bow is rated at 314. I only have 28 inch draw. I added a loop, peep etc and then a 450 grain arrow. I'm all the way down to 258 fps.

So-called 'IBO speed' is scaled at 30" draw length, 70 pounds draw weight, 350 grain arrow. NO string accessories, not even a nockset. And since it's unofficial andhas no authority as anindustry standard,there is no guarantee that they won't fudge the draw weight or draw length a little bit to fluff up the numbers.

Anyway, less draw weight, shorter draw length, more arrow weight, addition of string accessories (nock set, silencers, peeps, loops, kissers, etc) will all cut down the speed. Often significantly.

Your shooting mechanics can affect speed. If you allow the string to creep forward before you release, you've cut speed off your arrow.A bow's tune will also affect speed. If it's even the slightest bit out of adjustment, it can cause a drop in speed.

If you'd like to see theauthentic, real deal archery industry standard method for testing arrow speeds, it's ASTM f-1544-99. You won't find 'IBO' in there anywhere. Here's a link to it:

http://peteward.com/ASTMstandard.pdf

Arthur P:... all that Pete Ward stuff makes my head hurt.[&:]

You need to realize that IBO and AMO speed ratings are nothing more than a comparison point. Yes MOST of the time, that bow, setup properly to match IBO/AMO criteria will hit that number, or very close.

Setup for real use, probably won't hit that number, especially IBO. Setup for hunting and nope, not gonna get it. If you don't shoot a 30 inch draw, nope not gonna get it.

I spent so many years dealing with military specificationsfor aircraft and missle partsthat the AMO specs are pretty darn mundane. Didn't even think about the agony it could cause the uninitiated. Sorry, Dave...