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My First Attempt at Calculating FPS/FPE

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outdooorgb

outdooorgb

Member
Feb 8, 2021
117
81
OR, United States
The Avenger is new to me and my first PCP. I wanted a chronograph and they are not free. During a search I found someone who checked out the inexpensive VIKKA at $33.
As far as accuracy? I believe I'm in the ballpark but really what I have is a baseline. Someone online compared two stings, one from this unit and one from a higher end with similar results.

I bought this: https://www.amazon.com/dp/B08DRJ3JW7?psc=1&ref=ppx_yo2ov_dt_b_product_details

And set everything up today. Took 21 shots for no particular reason. You can see my results below for the Avenger and another for the HW97k. Both in .22
The unit can be set in fps, mps, and joules (with input). I just chose to record the mps and build an excel sheet to save.

Chrony 3.jpg
Chrony 2.jpg
Chrony 1.jpg
 
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outdooorgb said:
The Avenger is new to me and my first PCP. I wanted a chronograph and they are not free. During a search I found someone who checked out the inexpensive VIKKA at $33.
As far as accuracy? I believe I'm in the ballpark but really what I have is a baseline. Someone online compared two stings, one from this unit and one from a higher end with similar results.

I bought this: https://www.amazon.com/dp/B08DRJ3JW7?psc=1&ref=ppx_yo2ov_dt_b_product_details

And set everything up today. Took 21 shots for no particular reason. You can see my results below for the Avenger and another for the HW97k. Both in .22
The unit can be set in fps, mps, and joules (with input). I just chose to record the mps and build an excel sheet to save.

View attachment 325371View attachment 325372View attachment 325373
Click to expand...

Good job on gluing a piece of wood? in the middle to protect the far light. Wished I had thought of that before shooting out the far light on my first chrono.
 
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I have that exact chronograph. When you power on the device, it'll say On, then 888.8, then wait til it says PS then hit the button once and it'll say and swap to FPS. Never programmed mine and can't confirm it's accuracy. When I increase HS the FPS goes up, so it's gotta be close! Lol Also like how it can clamp down, and how light/portable it is. Definitely worth the $
 
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@outdooorgb that is a neat little unit. Thanks for sharing it with us. If you want to validate either the machine or your fps and/bc the Strelok Pro app has a function for that. It compares pellet drop between the scope's zero yardage with a further shot down range. Of course you can do the same math too, just like Strelok Pro does, but there all kinds of useful tools in it as well.

play.google.com

Strelok Pro - Apps on Google Play

Professional ballistics calculator
play.google.com play.google.com
 
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EmptyTin_Tim said:
I have that exact chronograph. When you power on the device, it'll say On, then 888.8, then wait til it says PS then hit the button once and it'll say and swap to FPS. Never programmed mine and can't confirm it's accuracy. When I increase HS the FPS goes up, so it's gotta be close! Lol Also like how it can clamp down, and how light/portable it is. Definitely worth the $
Click to expand...
The clamp-on version only has 3 digits. Not 4 and never displays 888.8 when "booting up".

So you do not have the "exact chronograph". You may have the other version, but not the clamp-on version.
 
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Yes mine is the 3 digit as shown in the Amazon link. That is it exactly and only displays mps.

Outdoorgb’s photo shows a 4 digit. Did you order from that link and get a 4 digit clamp on?


But this one is the 4 digit found at the bottom of the page.
 
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Two little LEDs. I read where a guy shot one and replaced it with one out of a tv remote.

It works in the dark. I bought one because I couldn’t get a Caldwell to work in my basement, and I didn’t want to fool around with light kits. This, for me, works so munch better, especially from a convenience standpoint. No set up, clamp to the moderator and shoot. That also keeps me from shooting the device. There is a huge thread on GTA about these. Well worth $30.

It does change the poi, so be mindful of that. Test speed and accuracy separately, and don’t shoot the wall...DOH!!!

The on off button stuck on my first one after almost two years.
 
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BackStop said:
The clamp-on version only has 3 digits. Not 4 and never displays 888.8 when "booting up".

So you do not have the "exact chronograph". You may have the other version, but not the clamp-on version.
Click to expand...
Sorry but I can't imagine what would make you think you can know what I "do not have" when it's literally the same one as in Post #1's link, as I said. I clicked that Amazon link and it says "purchased on xxx xxx date" at the top.

Anyway, here is proof showing my clamp on version. Which says... "Clamp-style" right on it.

IMG_20230122_064452653.jpg
IMG_20230122_064242285.jpg
IMG_20230122_064312984.jpg
IMG_20230122_064330642.jpg

Here's a picture of the underside that shows the sensors that capture the light from the 2 bulbs on the bottom. Pretty cool how it works!
IMG_20230122_064433500.jpg

And here are the instructions that came with mine in case someone wanted to try some different settings out. I just swap to FPS and don't do anything else. But if you want to there are multiple functions.

Sorry this is sideways:
IMG_20230122_065801118.jpg


IMG_20230122_065741446.jpg
 
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I clicked the second link above and shows a different brand that what I have...I have a VIKKA but they certainly look the same.
I didn't bother switching to FPS as the reviews states they reset when turned off. Working aerospace engineering I have no issues with metric, so I just left it as delivered and used the excel sheet for any conversions.

I did add some shrink tape to the U bolt and some electrical to the v-clamp for protection. I also added a piece of wood between the LED's to keep me from shooting the front one. Going to run the R7 through some paces this AM.
Chrony 4.jpg
 
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Yeah I got mine last June. So the 4 digit, FPS version been out a little while, and I do not do metric well. Lol So like it was stated yes it does reset every off/on so you have to swap to FPS. But real easy, just power on, wait for it to say PS then hit the button once and it says FPS.

Mine also came with the Chinese instructions but I was glad it also has English.

Great idea to add the shrinkwrap! Thanks for that-I'll have to copy you.

PS what do you think of your Buck Rail LDC? I got one and think it's a good design, it helps but doesn't make mine silent. Can't complain for the price though.
 
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Just finished running the Beeman R7
635 FPS (9.1 stddev which I though was large)
6.6 FPE (0.2 stddev)
CP Pointed 7.4 gr


So I did three guns this weekend. All using Crosman "inexpensive" ammo. I'll do it again in a few days with some upper-class ammo. Still learning and will play with the hammer spring a bit on the Avenger. I do enjoy being a geek...

The Buck Rail Moderator on my Avenger is night and day difference. Really works well. Gun is a "3" medium loud but comes down quite a bit with the BR.
 
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Nice chrony. I have one also. I had no idea it could be set to FPS until just now!
I don't use the u-clamp. I just use a couple of rubber bands to hold it to the muzzle. The u-clamp won't fit over a tatsu moderator.
Edit... I just looked at mine. It's the 3 digit and can't be set to FPS...
 
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