Looks like a new Chrono is next...

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Looks like a new Chrono is next...

Post by Rod_outbak » 31 Dec 2018, 5:33 pm

I think my 'Shooting Chrony - Master' chronograph has gone squirrelly.
Made in the good old US of A, and the gent who designed that user interface needs to be tied to a bull-ants nest...

The last few chrono results from this unit have become erratic, and I had the chance to test it against a mates PACT chrono today.
We fired 5 rounds from each of the following:
Ruger Precision Rifle .223 - mates rifle firing Hornady factory TAP 75gn loads
CZ 455 .17HMR of mine, using CCI 17Gn V-Max pills
CZ 455 .17HMR of mine, using CCI 17Gn Speer TNT pills
Tikka T3 7mm-08 of mine, using 120Gn V-Max reloads of mine
Ruger Precision Rifle .308 of mine, using 125Gn SST reloads of mine
Tikka T3 of my mates in .260, using reloads of his in 95Gn V-max pills.

We set the 2 units up one after the other, so we shot through both, with mine being second in line.
The PACT was about 3.5 metres from the muzzle, with my 'Master' about a metre further, and we got 'clean' reads on all shots fired(no errors).


Most of the groups tested as being 50fps faster through my chrono, though not all of them.

Most of the groups had nearly double the spread on my chrono, than my mates PACT chrono.

And yet, a couple of the loads came in nigh identical with my mates PACT chrono.

I've been through the poxed manual for the damn thing, and there's no function to re-calibrate the unit.
Besides; how would you?
About the only option would be using something that has a definite, repeatable & known velocity around the 3000fps mark, and there arent a LOT of those in outback QLD!
OR...using ANOTHER chronograph to test THE OTHER TWO chronographs!
[This will start to get convoluted...sigh.]

My theory is that the dust out here knocks the optical sensors around over time, and screws them up. It certainly seems to do that for other optical equipment, so cant see why an optical chronograph wouldnt be the same.

So, NOW I have to do a bit of soul-searching, and decide whether I am happy to go with a MagnetoSpeed chrono, or bite the bullet and go LabRadar.
I can justify either, as long as it works.
Both look to do the job, but the LabRadar appeals for the simplicity of use, and the more extensive mapping of each bullet's flight. The heavy power usage doesnt worry me, and it's unlikely I'm going to clock anything about 4000fps in this lifetime, so it's limitations wouldnt worry me.
I do like the idea of simply plonking it down beside me, turning it on, and firing away. ...

Decisions, decisions....
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Re: Looks like a new Chrono is next...

Post by brett1868 » 31 Dec 2018, 5:45 pm

Lab Radar...every day of the week :)
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Re: Looks like a new Chrono is next...

Post by marksman » 31 Dec 2018, 6:10 pm

IMHO I dont have a clue :wtf: :lol: :lol: :lol:
but this may help :drinks:

www.youtube.com/watch?v=8SpjRnYncpo
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Re: Looks like a new Chrono is next...

Post by straightshooter » 01 Jan 2019, 7:21 am

With all chrongraphs everything depends on what actually triggers the start sensor and what triggers the stop sensor and whether that variation is significant in relation to the distance between the start and stop sensors and in comparison to the resolution of the internal timing clock in the unit.
Virtually no consumer level chronograph can be used to obtain an absolutely reliable measure of velocity. What the manufacturers don't ever reveal is the true and reliable tolerance level on readings that may be obtained. At best it will be an approximation and will be most useful for comparison of similarly assembled ammunition.
All types ie; shadow triggered chronographs, magnetospeed and labradar have both strengths and weaknesses.
Some examples of what will be a source of error for a shadow triggered chronograph are:
Short distance between start and stop sensors.
Uncertainty as to which part of the projectile (ie: tip, ogive or body) generates the shadow triggering event in each of the start and stop sensors.
In a magnetospeed the relatively short distance available for detection must potentially impair absolute accuracy although repeatability may be OK.
I have no idea of the triggering mechanism within a labradar so I can't comment.
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Re: Looks like a new Chrono is next...

Post by Rod_outbak » 01 Jan 2019, 9:30 am

On my old CED Millennium chrono, there was an option to set the distance between the two optical sensors.
As the Shooting Chrony units use a set distance (Sky-screen mounts are integrated into the fold-open mount/box), there doesnt seem to be any option to adjust or re-calibrate the chrono. Certainly nothing in that POXED POXED POXED menu that suggests it can be edited.

But even more of concern, was the fact that my chrono seemed to vary it's results more than the PACT chrono we were comparing against.
For some groups, my chrono had a spread of double that of the PACT for the same shots, in some groups, my spread was nigh identical, and in some groups, the spread was over 3 times as high.
So, aside from trying one last thing to see if I can get a bit more reliability, I think the Shooting Chrony Master is to be retired.
When I compare yesterdays results against the results I took last week with 3 of the same rifles, my chrono seems to have them with notably higher velocities for the very same ammo as tested last time. Same time of day, exact same ammo (even same batch), and same temps/sunlight/etc etc.
Inconsistent.

From what I have read about the LabRadar units, they have an audio trigger (built-in microphones), can have external trigger devices connected, or using the doppler radar itself(depends on the type of projectiles, but the internal microphones recommended for firearms).

I'm leaning towards the Labradar for ease of setup & use, which equates to me testing loads more regularly.
However, I shall ponder it some more, before taking the plunge.
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Re: Looks like a new Chrono is next...

Post by Ziad » 01 Jan 2019, 11:27 am

I think i have said it superhersomewhere else. I got my nagnetospeed sporter for 250 from a shop...that's now closed. At that price it was a no brainer.

It does effect poi (and possibly groups, need to do more testing) but its very simple to install very small and works for me. If money was no object and the best was required then possibly the reputation of lab radar wawould male it the winner.

But got a shooting mate, hes got an optical one. ..not that he uses it a lot but his ammo is just superb. Even i can get some very accurate groping on my worst day.
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Re: Looks like a new Chrono is next...

Post by Sako308 » 01 Jan 2019, 11:42 am

If you want an accurate velocity detection everytime with those calibers, then MagnetoSpeed is the go. Ive found with the MS that once you've setup the bayonet for height the first time, then you rarely have to mess with again, unless you're going from a heavy barrelled .22cal to a sporter barrelled big cal. but then its a simple matter of adding or removing a spacer and confirming bore clearance with the rod.

From what Ive read on the inter-webs the Labradar struggles with detecting small cal's, but I haven't had the opportunity to test it myself.
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Re: Looks like a new Chrono is next...

Post by SCJ429 » 17 Jan 2019, 7:48 pm

The Lab Radar picked up a 20 cal (204) easily but then I could not pick up a big bore. Probably operator error but I tried everything and only got readings on three shots out of twenty.
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Re: Looks like a new Chrono is next...

Post by Stix » 17 Jan 2019, 9:00 pm

Hey Rod...
As Sako308 has said, the magneto is quick & easy to set up....

Obviously first couple of times takes a good 5 minutes, but most of that is both getting used to the unit, & getting over paranoia that you'll shoot the bayo off... :D

After your initial 'getting familiar with a new toy' time has elapsed, you will find you'll be up & ready to fire as quick as getting ammo out & loading a mag... :thumbsup:

If it happens that you need to add/remove spacers for different barrels, after only a few swapping rifle events you will know what to add/subtract by defsult & do it very quickly...

The main point i have with the magneto is, if you keep the outside of your barrels well oiled, have a dry rag handy & wipe oil off the end of the barrel before a session with it...
My tikka synthetic sporter weight 7-08 dances around a little when shooting off a bench & the magneto can slip forward a small amount every shot if "lubed", so wipe off oil & check it after a few rounds anyway... :thumbsup:
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Re: Looks like a new Chrono is next...

Post by Rod_outbak » 17 Jan 2019, 9:46 pm

Stix,

I hear you, but I keep coming back to the fact that I cant chrono the 1911 handgun with the Magnetospeed, that swapping between rifles is a bit more tedious than the LabRadar, the more detailed mapping of the bullet flight, and the simplicity of setup, are all leaning me towards the LabRadar.
Nothing against the Magnetospeed, but the LabRadar looks like it might work a lot better for what I have planned for it.

I can afford the extra $350, and it's likely to get a lot more use than what I'd get out of the Magnetospeed.

Cheers,

Rod.
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Re: Looks like a new Chrono is next...

Post by Stix » 17 Jan 2019, 10:55 pm

Yep...No worries Rod... :thumbsup:

I certainly wasnt trying to talk you into one... :)

You did mention the magneto is within your choice range, & as i have one i was just giving you some user feedback that may help you make your choice... :thumbsup:
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Re: Looks like a new Chrono is next...

Post by Ziad » 18 Jan 2019, 7:37 am

Hey buy a magnetospeed sporter and a labradar... problem solved. That's the solution of everything.... get all the calibers... maybe that's why I have ended up with 5 guns in 1 year :D

I got the sporter for 250 new, they are 320 from their AU distributor. The only issues with labradar I see was false reading from ppl shooting near you on the range. But I don't think you will have that issue Rob.
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Re: Looks like a new Chrono is next...

Post by SCJ429 » 18 Jan 2019, 8:42 am

Ziad wrote: The only issues with labradar I see was false reading from ppl shooting near you on the range. But I don't think you will have that issue Rob.


You don't get false reading but it triggers an error saying it detected a round but didn't record a speed. It is a pain because you have to press enter to reset. You get back behind your rifle only for someone else to fire a shot and trigger another error.
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Re: Looks like a new Chrono is next...

Post by No1_49er » 18 Jan 2019, 9:51 am

Over the (many) years, I've bought several chrony's. First was a Oehler 35P. A CED II next and finally a Magneto-speed. Each has its uses.
MS is good for quickly checking velocities after load development.
The CED has an easily set up screen arrangement that is perhaps limited in its accuracy by the short screen spacing.
And then, there is the Oehler. It's what might be called "old" technology, but that doesn't detract from what it is supposed to do. The major advantage is that it has three screens which means the velocity is measured twice for each shot. This provides a "proof" check that verifies the accuracy. I have a rail that is 8ft long, meaning 2x 4ft spacing screens. There is an option (user selectable) to use screen spacing from 1ft to 15ft. The greater the distance the more reliable the accuracy.
Oehler has been around for a long time and a lot of his work has been in the development and supply of chrony's for the military who have somewhat demanding expectations for their equipment.
I've no idea if there is an Aus. distributor - I bought mine direct, which was a very easy matter all those years ago. The $$ was a bit better at the time.

It's probably also worth adding, in relation to a previous posters' frustration at not being able to "re-calibrate" his chrony. The velocity will be derived from the time difference between the detected light change at the screens. The internal clock, in all likelihood, will be fixed within the electronics, much like a digital watch.
If it really is inaccurate (how would you know?) perhaps it's worth doing a side by side check, and if it can be shown that your machine is defective, a replacement is probably the only realistic "cure".
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Re: Looks like a new Chrono is next...

Post by Stix » 18 Jan 2019, 10:46 am

SCJ429 wrote:
Ziad wrote: The only issues with labradar I see was false reading from ppl shooting near you on the range. But I don't think you will have that issue Rob.


You don't get false reading but it triggers an error saying it detected a round but didn't record a speed. It is a pain because you have to press enter to reset. You get back behind your rifle only for someone else to fire a shot and trigger another error.


Ive had magnetospeed trigger from a few other rifles...
I remember a 25-06 on the next bench triggering it a couple of times one day....
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Re: Looks like a new Chrono is next...

Post by pomemax » 18 Jan 2019, 12:34 pm

Hey Rod
For comparison you may try reversing the order of the chronographs .
We set the 2 units up one after the other, so we shot through both, with mine being second in line.
The PACT was about 3.5 meters from the muzzle, with my 'Master' about a meter further, and we got 'clean' reads on all shots fired(no errors).
just for comparison I was wondering if it would make a change .
You need to be far enough away that the muzzle blast doesn't affect ; the gas exiting the muzzle is faster than the bullet and can cause false readings
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Re: Looks like a new Chrono is next...

Post by Rod_outbak » 18 Jan 2019, 1:26 pm

Pomemax,

Unfortunately, the other chrono lives 700 kms distant, so it's going to be a while before I'll get the chance to have it back here again.
We did ensure we had a good 'read' happening; my master chrony displays errors every few shots from the gasses(if you have it too close).
The whole time we were running the pair of them, we didnt get either unit show up one error.

My greatest suspicion that my Shooting Chrony is going squirrelly, is the mates PACT unit seemed to give consistent results the whole time. However, my chrony started out reading higher speeds, and by the end of the session, was reading slightly slower speeds. If it had been consistently reading say ~150fps higher each time, I could almost live with that. But it was all over the shop.
I have a sneaking suspicion that the dust here plays havoc with the optics on chronographs. I say that because my CED Millennium chrono seemed to suffer the same fate; the results got more and more erratic as time went on.

I might mention it to the mate, though; he said he was likely going to be back out before Easter, so maybe there's a chance he can bring the PACT for a follow-up test.

Cheers,

Rod.
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Re: Looks like a new Chrono is next...

Post by trekin » 19 Jan 2019, 4:01 am

No1_49er wrote:Over the (many) years, I've bought several chrony's. First was a Oehler 35P. A CED II next and finally a Magneto-speed. Each has its uses.
MS is good for quickly checking velocities after load development.
The CED has an easily set up screen arrangement that is perhaps limited in its accuracy by the short screen spacing.
And then, there is the Oehler. It's what might be called "old" technology, but that doesn't detract from what it is supposed to do. The major advantage is that it has three screens which means the velocity is measured twice for each shot. This provides a "proof" check that verifies the accuracy. I have a rail that is 8ft long, meaning 2x 4ft spacing screens. There is an option (user selectable) to use screen spacing from 1ft to 15ft. The greater the distance the more reliable the accuracy.
Oehler has been around for a long time and a lot of his work has been in the development and supply of chrony's for the military who have somewhat demanding expectations for their equipment.
I've no idea if there is an Aus. distributor - I bought mine direct, which was a very easy matter all those years ago. The $$ was a bit better at the time.

It's probably also worth adding, in relation to a previous posters' frustration at not being able to "re-calibrate" his chrony. The velocity will be derived from the time difference between the detected light change at the screens. The internal clock, in all likelihood, will be fixed within the electronics, much like a digital watch.
If it really is inaccurate (how would you know?) perhaps it's worth doing a side by side check, and if it can be shown that your machine is defective, a replacement is probably the only realistic "cure".

What screen spacing does your CED have? Mine has a spacing of 2 foot (600 mm), which is nearly twice the distance of most comercial/comsumer units, with the option to go to 4 foot.
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