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magnospeed chrony

03 Dec 2015
@ 07:56 pm (GMT)


Anyone got a magnospeed chrony?
One big question.... wouldn't the fact it's strapped to the barrel effect barrel harmonics
Therefore groups or loads?


03 Dec 2015
@ 08:35 pm (GMT)

Warwick Marflitt

Re: magnospeed chrony
Is it steel on steel or has it got a decent rubber bush? I have wondered if barrels behave like a tuning fork? Has anyone ever used one load and progressively shortened the barrel between groups to see how it changes the accuracy by only changing barrel length.?
Some car exhaust systems have a steel clamp with a round rubber block attached to it? Apparently too inhibit harmonics..... someone will have studied this and know how it works. ..... it's no doubt copyright and for sale..............
03 Dec 2015
@ 09:09 pm (GMT)

Nathan Foster

Re: magnospeed chrony
A tuning fork indeed.

There have been rubber bushings designed to dampen barrel harmonics in the past. I have seen the results with these and they can help a wee bit. However, as I have written in the past, there is great room for the creation of a superior product for dampening. A product which can be clamped on but its location changed and or rotated if it were of a non concentric shape and weight. I have mentioned this to young machinists wanting to create something new, yet most do not even give it a try and instead jump on the suppressor wagon, watering down the already limited local market.

Getting back to your question Jason, I have not tested this chrony. As you say, there is a potential for problems. Also gas distribution. However, a retest of loads without the chrony would soon confirm whether past sweet spot loads are still the same. It is always important to double check sweet spot loads. Still, this particular scenario may be off putting to many.

I don't like to see anything touching my barrel, especially when I am chasing the last .1 to .2" during extreme accuracy work.

04 Dec 2015
@ 12:03 am (GMT)

Chris Bayley

Re: magnospeed chrony
I have one of these chronys and I'm comfortable saying it will change poi and possibly the precision. I tend just to check my speeds then take it off for the rest of my testing so I've never looked very critically at the difference but guess poi drops maybe an MOA and groups open by maybe an MOA.

It has a rubber pad and fabric belt so barrel damage is zero but with a high recoiling rig it can slide on the barrel a bit.

Overall it's it's useful and convenient so I don't get tied up about harmonics.

04 Dec 2015
@ 02:00 am (GMT)

Martin Taylor

Re: magnospeed chrony
Have seen one of these in action and it seemed to raise PIO & possibly a small effect on group size (heavy Varmint Barrel).

Very consistent & repeatable with velocity readings though. The owner uses it in the same way as Chris or Nathan has said, to check node speeds rather than leaving it on during all ladder testing!
04 Dec 2015
@ 03:04 am (GMT)


Re: magnospeed chrony
Yes. So as expected it must have effect.
See I like to shoot all load development through the chrony so I can watch groups, es and speed At the same time. I wouldnt want to do this separately. As I'd have to run a heap more rounds and testing.
I'm not sold. They can keep it.
04 Dec 2015
@ 04:25 am (GMT)

Chris Bayley

Re: magnospeed chrony
I'll do a rough calc of the load I'd want to achieve a target vel the make a couple of loads at that to see how close I am and adjust if necessary. Once I'm in the zone I want I'll take off the chrony and find the nodes I want. When I've got them I'll check and record their speed.
06 Dec 2015
@ 01:56 am (GMT)

Mike Neeson

Re: magnospeed chrony
Brian Litz has tested the various Chronys at length and compares them in this article. From memory he found the magnaspeed the most consistent and accurate recorder of MV.
06 Dec 2015
@ 10:45 pm (GMT)

Martin Taylor

Re: magnospeed chrony
I wouldn't write them off as they are bloody accurate as light levels etc don't mess with them.
My development is very different, I don't do any load development ladder tests over my Chrono, ever. I may pre-empt charges to some degree but the rifle & load combo will tell me what it likes and "is what it is".
Brass/primer (pressure), group size & general feel all come before speed. ES could be an Issue but shouldn't if you are following Nathans Reloading steps.

Once the highest node is found I load this and either side to confirm it's robustness both cold & hot bore. If still happy l check it at 300 cold bore with my hunting rifles over my Chrono to help set up chart Fps, job done, start LR conformation testing.
So five "possibly wasted" shots at the end to get an average fps over a very accurate Chrono that could be used under any weather conditions isn't much to add.

Have seen a few F1's at the range get bullet holes through them too, hahahahahaaa
07 Dec 2015
@ 02:36 am (GMT)

Eloy Vilavella

Re: magnospeed chrony
I am intersted to know how accurate is and consistent at reading.
IMO The accuracy testing should be separate from speed spread testing.
Get your accurate round worked and then get an idea of the spreads and
Done. managing the Other variables is far more important than squeezing
A few extra m/s.
The truth is printed on paper (Groups) and knowing more about bc corrected
Values, temp impact on loads, bp or even a small mistake rwading the wind
Has far more impact than super accurate speed references.
Also when working accuracy loads nothing should be touching the barrel that is not
Going to be there when the load is goung to be used in the field chrony or
Fir important to know how consistent the magnetto system is.
Initially should not be more forgiving than those with light sensors
That can be picky due to the light.
I am also worried about the short distance and how a small mistake in
Dimension can have a larger impact in the reading.
After all the most accurate industrial readers are a couple of meters long for that
Reason. There is always going to be an error the question
Is how much and also if the error is consistent.
The 2nd gen Magnetos seem pretty food.


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