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View Full Version : What is your Chrono procedure?



Boski51
12-25-2004, 01:41 PM
I am getting HUGE variations when I chrono. Why?

I am using a ULE Pro with L10. 900-950 psi into the marker. Shortest spring. Chrono a shot: 320. wait chrono again after 1 second: 290. again: 287 again: 301 again: 270.....and so forth.

Trying to get to a consistant 280 to 285. Are you suppost to shoot quickly over the chron? We use the small handheld deal that you have to reset every time-can't shoot quickly over the chron....

Why would the darn thing fluctuate so much....frustrated. This is not the only time it does it...every time I try to chrono at the field it takes me forever to drop below the 285 limit. I usually have to play way below 285.....sucks!

What am I doing wrong?

danheneise
12-25-2004, 02:04 PM
don't know if you're doing this but with the xvalve/rt valves you have to shoot a shot, then hold the trigger, then let go and pull again as fast as you can. this is to simulate rapid fire since the air dosen't come into the valve until you let go of the trigger, it won't have had the time to cool off and there for show you your rapid fire fps. if you don't hold the trigger down this lets the air cool down and will show a lower fps

Carbon Blue
12-25-2004, 02:04 PM
i used to get the same thing with my Lvl7 bolt. I would get fluctuations in the +/- 20fps range. I have yet to chrono my xvalve.

What kind of tank do you have?? I know that some regulators on some tanks dont recharge fast enough which would explain the huge fluctuation. I used to run an aci bulldog2 on my lvl7 which could be the explanation why it was fluctuating so much. But other than that i have no idea why the numbers are so off.

saml604
12-25-2004, 03:29 PM
most likely your problem is a bad reg seat:
http://www.automags.org/forums/showthread.php?s=&threadid=7291

Boski51
12-25-2004, 03:53 PM
After reading the instructions AGAIN, I lowered the marker pressure to 700 as they state. I fully pressed the trigger and fully released the trigger the same way each time.

The Chrono still varied widely, but this time in the 270s to the low 300s. Most shots were in the high 280s and mid 290s. Better, but still no consistency at all.

My buddies L-10 was 285 out of the box and never varied more than 5 fps. He shot three times no hot first shot and no shoot down. He was using a preset at 800 psi. I am using an Apocalypse 2K.

How do you all chrono....just walk up and rapid fire three off and your good?

trains are bad
12-25-2004, 04:36 PM
pretty much. It's never been a problem.

It couldn't hurt to put a new reg seat in it. Also, remember, mags like oil. Oil is your friend.

Boski51
12-25-2004, 04:42 PM
I am going to try that. Stupid question: Is the reg seat for the Level 10, X Valve, the white flat o-ring that is under the shims and carrier or is it the white o-ring inside the carrier? :tard:

Joni
12-25-2004, 08:45 PM
heres the reg seat:
http://store.airgun.com/index.cfm?fuseaction=catalog.prodInfo&productID=116&categoryID=23


Check here to see where it goes.
http://www.airgun.com/downloads/retroexploded1.pdf

Carbon Blue
12-25-2004, 09:19 PM
can the regulator seat on the retro/emag/xvalve be used over again once you open the valve just for regular cleaning?? because i know on my lvl7 bolt once you opened the valve the regulator seat would need to be replaced. :confused:

lautt
01-07-2005, 12:08 AM
can the regulator seat on the retro/emag/xvalve be used over again once you open the valve just for regular cleaning?? because i know on my lvl7 bolt once you opened the valve the regulator seat would need to be replaced. :confused:

really???? never heard of that.... :confused:

codeman35
01-07-2005, 12:54 AM
I've heard of that, but wasn't too sure if it was true or not.

deathstalker
01-07-2005, 12:15 PM
Yes, you should replace the seat on Classic valves just to be safe. There is information in one of the stickies about why. I'd have to go back and look at it myself to see if it applies to ReTro/RT/X-valves.

As for chronoing, keep in mind there are a number of factors that will affect your velocity. Is the paint in good condition? Does it fit your barrel well? Do you have a fresh fill? Does the chrono have a fresh battery in it? If that's all good, you MUST make sure you chrono using the proper procedure. You don't "just walk up and rapid fire three off and your good".

1. Shoot a ball, NOT over the chrono, and hold the trigger after you fire it.
2. Now, put your barrel over the chrono, making sure it is horizontal and not angled down like most people do. If you're using a handheld, don't hold the chrono against the barrel.
3. In one motion, release the trigger and pull it again to fire a ball. You MUST do this as fast as you can. Just as before, keep the trigger held.
4. Reset the chrono and repeat step 3.
5. Reset the chrono and repeat step 3.