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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Sharing the extreme love with cats in Outback QLD