Chronograph Usefulness

[DeltaBravo]

I've got a chrony and I'm wondering whether upgrading to a Magnetspeed is worth the cost? I shoot short range BR and I'm curious about how important or valuable a chrono really is. Since starting a couple years ago, I've used the chrony only a few times (PITA to set up), but I'm wondering what I'm missing by not using it more often when working up a load or tuning a rifle.

Ideas?

Dennis

 

[Romulus]

Optical and Magnetic chronographs both have their place. The Magnet fans say optical is not as reliable and I'd have to concede in theory in terms of precision but not necessarily in consistency.

But I've also seen loads developed with Magnetospeed that went to total dog crap when the gadget was removed. I think of Magnetospeed for grabbing velocities or checking a developed load's stats, but i still think checking consistency of a load without adding harmonic variables (nor POI Shift) using an optical chronograph is a cornerstone of load development.

That said, I will buy a Magnetospeed someday, as there are SO MANY situations where loading, setting up, and getting an optical working is a PITA.

 

[fdshuster]

Dennis: I also got fed up with a conventional chornograph. Spend all the time setting it up, having to go in front of the firing line repeatedly, etc., then have the thing fail after only a few shots fired.

Bought a new VH-1 Magnetospeed 2 years ago when they first came on the market & have never regretted the purchase. Everything needed is stored and carried to the range in a 14" x 9" x 4.5" case, 2 minutes required to start shooting, even less time to remove it & put it away. Never step in front of the firing line, and works under any and all light conditions, even near zero. Have never fired a shot and not had it recorded. 100% reliable.

It's reassuring to run tests of various loads and compare ES and SD numbers, and verify that the lower the numbers, usually, the smaller the groups. Also nice to have velocities recorded and go into ballistic charts to get your clickups for the longer distances, without having to do the shooting, especially when the distances required for a "live" sight-in are not available at the time.

Could I get by without it? Sure, but it can be helpful.

 

[Joe R]

Dennis,
I have an Oehler 35P and it works like a charm. It is a PITA to set up. If you get another guy to stand and look through your scope while you're setting up the chrony and the target is 10 times easier. I tell guys at the range that I'll pay them $10 for ten minutes of their time if they help me set up, and 4 out of 5 times they don't take the money. They are just glad to help.

I've just started using it in conjunction with QuickLOAD, that's were you see the real benefit.

Kindest regards,

Joe

 

[jrm850]

I got tired of dealing with missed readings with the opticals and bought a steinart. It couldn't be easier to set up and it hasn't missed a pickup yet, but it is missing a lot of the bells and whistles that most of us expect. When I was deciding between the magneto speed and this one, I started thinking about how effective a tuner was at changing groups and picked the sonic. I can't vouch for the accuracy yet but so far it's working great as a reference tool.

 

[6BRinNZ]

Not sure why you want a chrony for short range BR. Highly unlikely that a magneto would be useful for this discipline.
I use a magneto for F-class frequently on club days...but I'm not so worried about group size just confirmation that my numbers hold under match conditions.

 

[stool]

i to have a 35p, and do not understand the IDEA of hanging a weight on the end of a bbl i am testing loads in..no sense at all.
has to play with harmonics..ask any tuner maker....

the big advantages is when you combine YOUR data with a tool like quickload.
you can use YOUR real world data for all future calculations.....some of my powder in my guns burn and produce a lot less energy per pound kj/kg.......some produce more..i log all this data and make going to the range with "test" load a much quicker.shorter task.

you can log your case volume, your kj/kg, experiement with what happens if you seat longer or shorter......and then go shoot with confidence...

 

[artbosco]

I've got both the old style and the magneto. In my humble opinion they're only good for historical data on velocity; after you've worked out the load, fine tuned with seating depth and neck tension, and have bullets going through the same hole. I rarely use them. Only when I get curious about bullet speed. The magneto is convenient, nothing elaborate to set up.

 

[watercam]

Having had two other chronographs over the last 20-odd (plus a little) years I purchased an Oehler 35-P and have been breathing a sigh of relief every time I pull the trigger. Just in time to hear about a Dopler Radar chronograph soon to come to market for less money and zero set up. Isn't that JUST the way it goes!?!?!

 

[JamesnTN]

One thing that a chronograph comes in very helpful with is watching for load spikes as you work up your loads. As the charge increases so does the velocity, then you reach a point that you'll see the velocity begin to fall off, then out of no where that next few tenths of grain you'll see a spike in velocity and of course pressure as much as 120 fps just over 2-3 tenths of powder. Those that know what to look for will observe and know when to stop or keep going. This has saved me in the past on load development on wildcat cartridges that could had damaged a bolt or an action. So as you use a chronograph not only use it to test your velocities and extreme spreads but as a tool to pressure spikes and from hopefully blowing a primer and messing up the bolt face or worse an action.
I've argued a many words over on SH how the magneto speed will affect poi of groups but they claim it don't but that's difference between those of us that squeeze our accuracy down to the .1's and those who squeeze down to 1" it may be a pain to setup the typical chronograph a but the time spent is worth it in the end. Also some advice the farther you can space the sky screens from entrance to exit of the bullet across the chronograph the more accurate it will be. This is one reason I prefer the CED over other brands well except for my model 82 that's the cats meow.

 

[6BRinNZ]

One thing that a chronograph comes in very helpful with is watching for load spikes as you work up your loads. As the charge increases so does the velocity, then you reach a point that you'll see the velocity begin to fall off, then out of no where that next few tenths of grain you'll see a spike in velocity and of course pressure as much as 120 fps just over 2-3 tenths of powder. Those that know what to look for will observe and know when to stop or keep going. This has saved me in the past on load development on wildcat cartridges that could had damaged a bolt or an action. So as you use a chronograph not only use it to test your velocities and extreme spreads but as a tool to pressure spikes and from hopefully blowing a primer and messing up the bolt face or worse an action.
I've argued a many words over on SH how the magneto speed will affect poi of groups but they claim it don't but that's difference between those of us that squeeze our accuracy down to the .1's and those who squeeze down to 1" it may be a pain to setup the typical chronograph a but the time spent is worth it in the end. Also some advice the farther you can space the sky screens from entrance to exit of the bullet across the chronograph the more accurate it will be. This is one reason I prefer the CED over other brands well except for my model 82 that's the cats meow.

POI or Tune (group size)? There is plenty out there that shows the magneto affects POI (in some configurations)...I can vouch that POI is absolutely 100% affected for my setup. But I haven't done any testing as to impact on tune.

 

[jcampbellsmith]

I wouldn't be without my Magnetospeed now. I wasted so much time and money last year with other chronos.

https://dl.dropboxusercontent.com/u/12296998/Magnetospeed/GAT%20Rifles%20260%20Rem%20%2B%20MagnetoSpeed.jpg

I went to a shoot recently and my drops were spot on.

Regards

JCS

 

[DeltaBravo]

Thanks for all the great replies, folks!

I guess my original question should have been how useful for point blank BR and I'm thinking that answer is "not so much" as a couple folks said. Maybe I was just looking for some excuse to get the new toy, : but I think I'll buy new wind flags instead! 8)

Thanks again for clearing my cobwebs and helping me put my money to "better" use!

Dennis

 

[amamnn]

for those folks who insist on using the old style chrony:

Remember your scope is not your bore--and -- using your bore sighter --in bore laser type-- to set up the chrony will save a lot of grief.

That being said-- I have not found any real world correlation between chrony info and group sizes, especially, as mentioned above at short range BR distances. Having owned 3 --one an Oheler that got shot by a former friend---I cannot say that I have found then to be worth the time trouble and expense when doing load development for cartridges to be shot at known ranges. As in BR shooting.

If you need to be able to predict your load's trajectory over a long range in order to hit targets at varying distances--they can be of some use.

I had a math prof laugh at me when I explained all this chrony stuff at a party. He explained what it takes to statistically significant sample in order to predict things like this---you'd have to be sponsored to be able to afford to shoot so many rounds........so seems that the chrony benefit is one of those things that can be more apparent than real................

 

[Judd]

Longer range stuff I think ES/SD numbers can be beneficial but for short 100/200y stuff I don't think I would spend the $. I also am of the camp hanging anything on the barrel disrupts barrel harmonics. When I use a chrono it is normally for load development and I need the barrel to behave as it would later and in my beliefs it cannot with a chrono hanging off the end.

I still use the Oehler...I set my gun up and then quickly (like less than 2 minutes) set my chrono out in front of the gun.

 

[jlow]

I don’t think a chronograph’s only use is to give you MV so that you can predict the dope you need for long shots. MV can be used to tell approximately how hot your rounds are and close to an accuracy node/max pressure, plus most importantly, the consistency of your MV (i.e. ES and SDev) will give you important information as to how consistent your reloading procedure is. Certainly if you neck tension is inconsistent, it will show up in those two numbers.

 

[stool]

yep es and sd are based on LARGE sample sizes as in 1000's...not the 3/5/10 shot samples most of us do....
having said that, yes it is not STATISTICALLY significant, but it is one more reference point for the ammo crafter.

if you are a lemming, one who shoots 6 ppc with x bullet weight and y amount of vv powder...you do not need a chronograph...the current sport is a very forgiving set of variables...

I had a math prof laugh at me when I explained all this chrony stuff at a party. He explained what it takes to statistically significant sample in order to predict things like this---you'd have to be sponsored to be able to afford to shoot so many rounds........so seems that the chrony benefit is one of those things that can be more apparent than real................

 

[6BRinNZ]

yep es and sd are based on LARGE sample sizes as in 1000's...not the 3/5/10 shot samples most of us do....
having said that, yes it is not STATISTICALLY significant, but it is one more reference point for the ammo crafter.

if you are a lemming, one who shoots 6 ppc with x bullet weight and y amount of vv powder...you do not need a chronograph...the current sport is a very forgiving set of variables...

I had a math prof laugh at me when I explained all this chrony stuff at a party. He explained what it takes to statistically significant sample in order to predict things like this---you'd have to be sponsored to be able to afford to shoot so many rounds........so seems that the chrony benefit is one of those things that can be more apparent than real................

This is where a magneto is great. I have regularly used mine out to 900 yards on F-class club days to build the data. No extra trips to the range and the data is built up under match conditions.

 

[Catfur]

yep es and sd are based on LARGE sample sizes as in 1000's...not the 3/5/10 shot samples most of us do....
having said that, yes it is not STATISTICALLY significant, but it is one more reference point for the ammo crafter.

if you are a lemming, one who shoots 6 ppc with x bullet weight and y amount of vv powder...you do not need a chronograph...the current sport is a very forgiving set of variables...

I had a math prof laugh at me when I explained all this chrony stuff at a party. He explained what it takes to statistically significant sample in order to predict things like this---you'd have to be sponsored to be able to afford to shoot so many rounds........so seems that the chrony benefit is one of those things that can be more apparent than real................

30 should be sufficient for a decent sample size (see Central Limit Theorem). The larger the sample size, the more likely the sample average and the sample standard deviation are "close" to the population average and standard deviation, though. But 30 is generally considered enough to have a valid sample.

 

[jlow]

Yes, that is correct. Those huge sample size is really only needed in studies where there is a lot of noise like trying to figure out whether certain genetic traits has a specific effect. It really depends on what you are trying to prove, but for the kind of studies we are doing, even an n=30 is statistically significant. Certainly you will need to reproduce the results in more than one study but I can tell you that data like that is accepted by the best refereed medical journal and of course the FDA – as I can speak from first hand experience.