Chrono tips

[TexasStick81]

I'm planning on trying to Chrono a few bows this weekend.  Any tips on getting accurate reads would be appreciated.  The plan is the same arrow shot 3 times from each bow.  3 feet from the chrono.  

Any do or don'ts related to light, how far to have the target behind the chrono, etc?

[LB_hntr]

havent shot a bow thru a chronograph in aobut 20 years so i dont have any tips on the actual process.
But I will say if you are planning to compare bow speeds make sure you weigh the draw weight of each bow at your draw length on the same scale. you would be surprised how many bows are not the actual weight specified on the scale. not all scales are the same and not all calibrated the same. so weigh them on the same scale to see if they are actually the same or off by a couple pounds either direction. This way you wont pass judgment on a bow for being slower if its actually lighter, etc.

Make certain that you get a consistant hard release. This summer I saw two guys get a 15 fps difference. The slower readings came from the fellow with the longer draw.  The faster readings were from me.

[Caughtandhobble]

Make certain that you are shooting your arrow at a level plain with the chronograph for an accurate reading. As far as the distance, just make sure that your arrow has plenty of room to clear the chronograph before hitting the target.

I love shooting the chronograph from time to time, it's the best release check there is other than having Rod Jenkins standing beside you watching. When all of your arrows are shooting within 1 fps from the same bow, your release is at the very least consistent.

One more thing, make certain that the battery is fresh. An old battery can give out some crazy readings. All of the ones that I have ever used takes a 9 volt battery.

If you still have that Horne, don't be surprised when she blows the doors off the other bows, lol.

[gringol]

Don't do it.    

[Bowwild]

I love my chrono. Every bow I get my hands on goes through it. I also use it to check the impacts of certain add-ons such as silencers or different string types.  Frankly, and this undermines the value of a chromo, I find very little difference and no difference that matters at my bowhunting distances.

My most recent use was to compare a couple of all-wood risers to the metal riser I have been shooting since January.  I found the wooden riser bows I tested (Silvertip and Sasquatch) were 1-1.5 pounds lighter in draw weight than the 49.5# metal riser (TT). I almost decided right then and there to put the metal riser away and go with the Tip this season (I hunted the Sasquatch last year). But, in the end the grip of the TT kept it in my hands.

I received some tips about Chrono use from some folks here about a year ago.  Some of this repeats above:

1. Fresh batteries
2. shoulder height chrono placement for level arrow entry and exit
3. About 4-6 feet away is fine, the arrow will be clear of the bow
4. The backstop should be far enough away for the arrow to exit the  chronograph.
5. Expect the first shot to be 1-3 FPS faster than the next ones. I don't count the first arrow in my shot string.
6. Of course a consistent anchor and release are essential if you are comparing equipment.
7. I shoot 3 arrows and expect at least 2 to be duplicate readings if not all 3.
8. Your chronograph may have tip instructions as well.
9. I had to buy the light kit for use on my home indoor range.
10. Don't forget to turn it off after use and batteries last a long time.

Finally, for me the chronograph is very revealing, especially about bow performance. One bow that I really liked I got rid of within days of putting it through the chronograph. I don't worry about 5FPS difference in the same draw weight but that bow was about 15 FPS slower than my other bows of the same specs.

[TexasStick81]

Thanks guys.  I appreciate the help.  I'll be clear, FPS is not the end all be all I'm just curious.  I agree that at 15 yards and in (the vast majority of my shots), the speed makes very little difference.  I'm much more concerned with how easily it draws and how smooth it feels when I release it.  Having said that, speed is one variable I'd like to know about.  

When comparing bows of various weight, how do you compare them?

[cacciatore]

Same light and temperature conditions are mandatory!

[Caughtandhobble]

When comparing different bows performance, I believe in matching grains per inch in arrow weight. By doing this it puts all the bows on a level playing field. What I mean is, 50# bow=500 grain arrows, 45# bow=450 grain arrows to get 10 gpi.

Like Bowwild mentioned the chronograph can be used in many different ways. I have shot a factory string compared to a custom "Skinny string", the results were amazing to me.

[TexasStick81]

I see the value in the GPI theory.  Given that what I'm looking for is real world performance, and I use the same AD trad lite with all my bows then I think I'll be using the same arrow despite various weight differences.  The data should tell me the difference in the exact bows I have rather than the optimal performance of a bow.  If a 45# bow is performing as well as a 50# bow with the same arrow and I can pull the 45 better and hold longer for a more consistent shot, then I may go with that having confidence that it can hit nearly as hard as the 50.  I'm looking forward to the tests, should be fun

[Dave Paradowski]

When comparing the perfotmance of bows, shoot ten arrows from each bow. Throw out the high and the low and average the remaining eight shots. This should give you a good idea about the performance of the bows....Dave

[Bowwild]

I use the same weight arrow for all comparisons. Then I divide the average FPS reading by the draw weight of the bow. This comes out with numbers such as 3.83, etc.  I have a spread sheet with a couple dozen bows which lists the bows according to this fraction. Actually, I've never measured a bow at my 26" draw with a number bigger than 3.8 something.

Interestingly, one of the best numbers I ever got was a new Grayling Green Super K I bought from the Gainesville, FL pro-shop a couple of years ago.

Other top bows are my Sasquatch, Silvertip, and TT.

Back when I had a closet full of Bear takedown limbs, I was surprized to find that my Schulz longbow was faster than all but one set of those takedown limbs. It did not seem that way when shooting, but the number kept repeating themselves until I had to believe it. The limbs that were faster were 7 pounds lighter than the longbow and the limbs that were slower were all about the same as the longbow and shooting the same 2020 shafts. Those lighter limbs were also autographed by Fred Bear, they were a replacement set for ones that blew up.