8 replies to this topic

[Deerhunter34]

I did a little chrono comparison with my crossbows today. I was a little surprised by the results.

I have a Parker Hornet Extreme advertised at 315 fps. I also have a Carbon Express Covert 3.3 advertised at 330 fps. Both manufacturers list minimum arrow weight at 400 grains.

For the Carbon express I chronoed 3 Surge arrows at 442 grains and 3 Red Hot Parker arrows at 410 grains.

    The Surge arrows averaged 285 fps.
    The Red Hots averaged 300 fps.

On the Hornet Extreme I only chroned the Red Hots at 410 grains because of the Capture nocks.

    The Red Hots averaged 309 fps.

The temperature outside was 37 degrees. All groups were three shot groups with consistency being within 1 fps.

Why was I surprised? My Parker is faster than my Carbon Express even though the CE is advertised to be 15 fps faster than the Parker. Neither met the advertised fps but I was slightly over minimum arrow weight with the test so I am not surprised. I am not sure how much temp differences make in bow oerformance. That test will have to wait till another day. I think I did chrono my Parker when I first got it but I don't remember what the reading was and I didn't document it. Anyway, have a great superbowl sunday!

Edited by Deerhunter34, 05 February 2012 - 10:00 AM.

[rock74]

Im not that surprised most manufacturers use terminology like up to x amount FPS, also to get the published FPS they are shooting arrows through a chrono that are lighter than the bows recomended bolt weight and what they tell us is dangerous to shoot.

[Highlander]

Interesting.  Which Chrono do you use? I'm thinking I should buy one.  

Edited by HighlandHunter, 05 February 2012 - 10:54 AM.

[Deerhunter34]

HighlandHunter, on 05 February 2012 - 10:51 AM, said:

Interesting.  Which Chrono do you use? I'm thinking I should buy one.  

I used the shooting chrony beta model.  Bought it a few years ago for reloading purposes.  It works well for me on everything from pellet rifles to handguns and high powered rifles and now crossbows.  Just don't lose the instructions.  The menu is not that user friendly.  I have to refresh my own memory by reading the directions because I only use it once in a while.  I believe cost was approx $100 when I got it.  You will also want a tripod to use it if you don't already have one.

[Fieldtip]

I've noticed that Parker crossbows (several models tested) meet or exceed the rated FPS. My Tornado with a 413 grain arrow shoots 334fps. and is rated at 330 with a 400 grain arrow.

[FuzzyFultz]

Good chrony information fellows, thanks.

                      Fuzzy

[See4miles]

For what it's worth, Last fall, I did chrony checks on two Excalibur Equinox models.  It was a father and son team.  They were shooting the prescribed arrow weight with Flemish strings just as Excalibur specifies for the 350 fps milestone.

Three shots were taken from each crossbow.  Results were: 5 shots/348fps   1 shot/349 fps if I recall correctly.

I'd call that living up to the spec.

[xbowguy]

There is no reason for weather/Temp to play a roll in speed especially when standing 1 yard from the chronograph.

Its SALES and Marketing boys!  Guess they will tell you Manufacturing Tolerance if you ask.  Why is it they never get to the high side of the tolerance?  I would be lying if I said in the past I didnt know that we were "fibbing" just a little on published arrow speed.

Could be a draw weight issue.  Its hard to make them all the same be it 150, 175 or whatever.  Figure 1 FPS per pound as a general guide.

[larryschooley]

I had low fps reading last year when I tested one of my crossbows. It was 9-10 fps slower that it was the year before. Had my crossbow tested somewhere else and it was right were it was last year. Turns out my crony was off.