Where's My Speed ????

[fellas2]

I've owned a Matrix 380 for about 5 years now and never bothered to get it chrono'd. A while back i was able to pick ip a good chrono real reasonable so today i thought i'd give it a whirl trying out the CenterPoint 300 Volt i bought the 8 year old grandson for his birth day. To my surprise the Volt chrono'd at an average of 301-304 fps with the factory bolts and 100 gr Dead Ringer Hyper Strike 3 blade fixed broadheads. So just for shits n giggles i brought out the Micro Nightmare 335 and with 16.5" BE Executioners, Ignitor nocks and brass insets (total 298 gr with tip) and 125gr Swackers, the best it would do is 292-298 fps. i switched to the 100 gr Dead Ringers and could only squeeze 304-307 fps out of it. The Micro has Air Brakes, Reds, and two small limb dampners and i knew i would loose some speed, but not that much. Now for the really scary part. I took out the Matrix 380 on which i recently put the Excal SDS system on it. It already had Reds and Air Braked on it, and with 18" BE Executioners carrying brass inserts and Ignitor nocks ( total 318gr without a tip) and using the same Swacker 125gr heads, the beast i could get is 300-305 fps. I switched to the 100 gr Dead Ringers and 309 fps was max. i checked the brace height and both are spot one. So, WHAT HAPPENED TO MY SPEED ?

[onebigskittle]

Sounds like it could be a chrono not doing right. I like a good sunny day to use mine and not under the trees where its a lot of shade

[fellas2]

Don't think the chrono is the issue. I'm in the bright sun and the Centerpoint is spot on with the rated speed.

[Boo]

The reason I have a light kit for my chrono is that readings are not reliable without it.
Your complete arrow has to be 350 grains to get anywhere close to stated speeds. Your set up is atleast 400 grains

[Normous]

I think the crono might be lying to you.
Where have I seen this before

[xcaliber]

Something sounds goofy and I’m with the group that the chronograph is the place to investigate.

[janesy]

Yep 100%. With arrows I only ever trust my Chrony when it shot indoors, in the dark with a light kit set up the exact same time every time. And always with new batteries.

By my math your 380 would be down approximately 45 FPS, possibly up to 50 depending on you string.

What makes me think you Chrony is not reading right is the difference you saw between 100 and 125. Reading are typically consistent even across platforms when you add or subtract weight. Yours is all over the map.

I would start by adding screens and lights, a new battery. ABSOLUTELY remove the luminock or any other translucent nock, and make sure you are shooting perfectly parallel to the Chrony

[janesy]

110% romove the luminocks. You cannot get a proper shadow reading with a luminock.

[Bcxbow]

110% romove the luminocks. You cannot get a proper shadow reading with a luminock.

Good catch Chris

[DuckHunt]

You didn't mention if you were using the diffusers (screens) on the chrony. I've noticed erratic readings on my ProChrono if I didn't use them even on a sunny day. So I make it a point to always use the diffusers. The lighted nock may be playing with things as well.

[fellas2]

I was using the diffusers for every shot. I just don't think it's the chrono since the Centerpoint is spot on the advertised speed. If anything, the readings would be higher for the Excels if the chrono was reading high.

[janesy]

Was the CenterPoint using illuminated or translucent nocks?

[fellas2]

Illuminated as well.

[janesy]

Also, you need to use field points over a chronograph. The chronograph reads the time it take for a shadow to pass over the front and rear sensor.

By using a Broadhead or any oddly shaped point, you simply cannot get a dependable reading. Add to the a clear or illuminated nock. You are asking for a clear crisp shadow from an oddly shaped object that refracts light best case ...worst case shines light right in the sensor.
Ditch the nock.


Further your specific setups.

Your Micro with a 423gr arrow and SDS kit should expect to loose ~41 FPS or more depending on string. So if say it's perfectly fine?

Your Matrix with an arrow weight of 443gr and SDS kit will loose 50 FPS. Would be low

However it has to be noted that the fact that your getting up to 10fps spread on your shots regardles, all points to your Chrony setup. My beta does that when the battery goes to 50%

[BCSteve]

My Micro 355 with a boo string shoots 415gr arrows at 340fps over my Chrono.