Which chronograph to get

[Yorric]

I have tested the Chrony with both the 17cm LED car running lights & also with the ribbon led strips that you can cut to length. It works fine. No flicker if you use proper DC current to drive them with batteries - not cheap mains adapters which often pass unstable voltages.
I take particular care to not try & use a chrony anywhere near neon or mains led lights as they do flicker & screw up the readings. - Hence the need for dark covers.

Ian

 

[Yorric]

Who'se got the oldest unshot Chrony?

I still have my first one going strong giving good results - Its the old red design that used card screens & not the rods. It is unshot. - It did once get a very heavy clout from the front end of my mate's moderator that failed & went downrange. - I'd added a makrolon front blast screen to the Chrony & that got shattered.

Ian

 

[Alantoo]

I have tested the Chrony with both the 17cm LED car running lights & also with the ribbon led strips that you can cut to length. It works fine. No flicker if you use proper DC current to drive them with batteries - not cheap mains adapters which often pass unstable voltages.
I take particular care to not try & use a chrony anywhere near neon or mains led lights as they do flicker & screw up the readings. - Hence the need for dark covers.

Ian

Thats good to know. The tunnel range at Monmouth has recently been upgraded from fluorescent to mains LED lighting since I tried (and failed) to get the Chrony to work there. But I will try some of the dc car running lights...I have a length of the heavy ribbon stuff but that is blue...the head torch that caused the strobe effect on my lathe chuck was dc of course but maybe that is just the overclocking that Ledlenser do to get the high output.

Alan

 

[deeangeo]

Who'se got the oldest unshot Chrony?

I still have my first one going strong giving good results - Its the old red design that used card screens & not the rods. It is unshot. - It did once get a very heavy clout from the front end of my mate's moderator that failed & went downrange. - I'd added a makrolon front blast screen to the Chrony & that got shattered.Ian

Bought mine, again an old red one, in 1994, but it doesn’t fit the ‘Unshot’ part of this!
But, it does still work OK

 

[Yorric]

Any LED driver that acts as a dimmer will give flicker if my electronic knowledge is correct - I may be wrong as I'm just a humble mechanical engineer LOL.

For indoor use, shade all mains voltage lighting over & around the Chrony & use unadulterated battery power. If you get too much light add more diffusion between the LEDs & the sensors (polythene milk containers work ok).

Ian

 

[Muir]

View attachment 92860
You mean like tonight? Weather app says it's supposed to get to - 36° tonight. Gun show in the city tomorrow wanna go?

Only -36? We should be out shooting while the weather is good.~Muir

 

[ChesterP]

I use a Prochrono and it has been reliable since the day it was bought in a wide range of lighting conditions. With a little care, there should be little chance of putting a bullet through one (mine mist have seen many hundreds or rounds shot over it now). What I like about them is the simple user interface and customer support offered, including some really useful options such as an indoor lighting kit, remote control and USB lead with PCremote software to connect with any laptop or PC.

It may not be as accurate as labradar but it's handier for me than a magnetospeed as I don't want something strapped to the end of the barrel upsetting barrel harmonics. For long range shooting, I usually try to verify velocities or BC anyway using measured drop data until happy that you have an accurate calibrated drop-chart/app solution for each load.

 

[aris]

When using a chrony - how far away from the muzzle do you put the device and what is your aim point? Dead centre of the 'V'?

 

[deeangeo]

When using a chrony - how far away from the muzzle do you put the device and what is your aim point? Dead centre of the 'V'?

10ft & centre of V for me.

 

[aris]

10ft & centre of V for me.

Thanks - this may well be a consideration when choosing a chronograph. If shooting at a range where it is not possible to access past the shooting line once shooting has commenced - or even not allowed to place devices there.

 

[PeterH]

I might well be wrong, but to my mind load development is all about getting the load right for the specific harmonics of your barrel. Strapping something to the end of the barrel must change those harmonics so you end up tuning your load to the barrel with the Magnetospeed attached. You can do your load development without it attached, but then you're not measuring ES/SD as you go which is all part of developing a long range load.

Nigel - read your entry but could not dispute shifting POI would happen with a Magnetospeed V3 attached as I have never tried it, so this morning put up a target at the usual 100 yds with my 20TAC and fired 4 shots at one bull (having given the scope three 1/4" clicks down) without the Magnetospeed then a further 4 shots at the other bull with the Magnetospeed attached.

There was no science to this experiment but apart from a smidgen it seemed to hold POI

PS Average 3712 fps and SD 6

 

[NigelM]

Nigel - read your entry but could not dispute shifting POI would happen with a Magnetospeed V3 attached as I have never tried it, so this morning put up a target at the usual 100 yds with my 20TAC and fired 4 shots at one bull (having given the scope three 1/4" clicks down) without the Magnetospeed then a further 4 shots at the other bull with the Magnetospeed attached.

There was no science to this experiment but apart from a smidgen it seemed to hold POI

PS Average 3712 fps and SD 6
View attachment 93192

That's very interesting Peter. Thank you. I stand corrected. Still don't understand how it can be the same though!

 

[ChesterP]

Anything hanging off the end of a barrel one would think will affect harmonics. However, the answer as to why POI is similar becomes more obvious when you look at barrel time and nodes. A good node usually coincides with the pressure wave (and axial node point) coinciding with the bullet as it leaves the muzzle. In load development times, this is usually manifest where you have a flat spot in velocities and ES either side of the node sweet spot. This being the case, the harmonics you might think should be the same at that point in time with or without the magnetospeed attached. Anything either side of that might see a shift at a guess.

 

[caorach]

Any LED driver that acts as a dimmer will give flicker if my electronic knowledge is correct - I may be wrong as I'm just a humble mechanical engineer LOL.

Yes that would be my understanding, as far as I know LED drivers tend to be, basically, switched mode power supplies. They work by switching on and off to control the amount of power they produce. They can operate at very high frequencies but they are effectively switching the LEDs off and on and so you get flicker. This is somewhat against what you'd expect, especially with a torch which is being supplied from a battery as your good DC source ends up driving an LED that flickers. To be honest I've no idea exactly what frequency it is "common" for them to work at in something you buy off the shelf but gather that most commercial lighting circuits are actually quite "slow" even if they weren't dimming, I can sometimes see car LED lights flicker for example and they aren't dimmable that I know of. I think you'd need to be very careful using LED lighting with a chrono unless you were very certain that the LED isn't being switched by something in the circuit.

 

[rem284]

I've got the Magnetospeed Sporter and for the price it's pretty good. Works in all weather, takes about 2 mins to set up, it's compact and light. Only downside is that it won't work with a moderator, you'll need the V3 for that buts it's the best part of £400. Not worth the extra in my opinion as the loads I developed (using the OCW too) have been accurate out to 500m so far with the velocity recorded without the mod. For about £20 you can buy an adapter that allows you to connect it to your smart phone and using the free app it can give you a better display and more info about trends/patterns ES/SD etc.

If someone wants to save money but normally use a mod when stalking would it be possible just to use the sporter version when developing a load and shoot without the mod on. I know there will be a poi change with a mod on and a mod off but is that a problem as long as you adjust accordingly

 

[Alantoo]

I used my friend's Steinert acoustic chronograph again on Wednesday evening. The first session I was again next to some anti social type with a muzzle brake and his blast also triggered the machine so we had to cycle through and read every other one to get my readings...they were quite different speeds so it was easy to figure which were mine and which were his.

The second session was next to moderated and unmoderated barrels and they did not trigger the Steinert....neither did they buffet me when I was taking aim.

The Steinert is so much easier to set up than the Chrony one...as long as the Acoustic unit is aligned parallel to the projected bore line and 3 metres in front...ie if the machine is 300mm lower and 200mm to the left you sight it to a spot 300mm lower and 200mm to the left of your target.

And away you go...well away I would have gone if I had not forgotten to turn it on...aaargh! I then had to ask the RCO if he would mind asking everyone to take out their bolts and allow me to go forward and turn it on...my first time at the range for a red face before I had pulled the trigger and demonstrated my marksmanship!

Alan

SuperChrono® Acoustic Shooting Chronograph Steinert Sensing Systems

 

[Border]

If someone wants to save money but normally use a mod when stalking would it be possible just to use the sporter version when developing a load and shoot without the mod on. I know there will be a poi change with a mod on and a mod off but is that a problem as long as you adjust accordingly

That's the route I took after replacing my Pro Chrono. Haven't used it much yet but appreciate the fact that just about every shot registers, unlike before

 

[NiemiPT]

Can you use magnetospeed sportster with sound moderator?

 

[Tom D]

Can you use magnetospeed sportster with sound moderator?

It depends on the size of the bullet and the diameter of the mod. I have the sporter and it works perfectly over the 7mm and an Aztec Maxim mod, it is less successful with the vartarg and the ASE Ultra mod. I think this is simply down to the tiny .20 bullets when compared with the big 7mm ones. If your mod is thicker it takes the sensor further away from the flight path, and if the bullets are small that will compound the problem.. FYI I would say that both my mods are about the same diameter..

 

[NiemiPT]

Ok. Thanks ��

My moderator is jaki super classic which is big and rifle is T3 CTR .260 rem. I think that I will save for labradar