Is a Chronograph really necessary?

[big ears]

Hi,

thinking of christmas presents and wondered about a chrono. Not into target shooting just reloading hunting loads in 223,6.5x55 and 308 which I have developed and am happy with the grouping I can obtain. Is owning a chronograph going to make much difference to these loads or my ability to shoot nice groups? Will it add anything to what I already have?

Cheers,

BE

 

[The deer man]

Yes!
If you don't know the speed of your rounds how will you accurately, or maybe I should say more accurately, calculate or have an indication you are working within safe pressures? I would also recommend a reloading program (e.g. Quickload), not completely necessary but a great help in addition to reloading manuals (up to date ones as well).
There may be other views but this is the one I work to.
​ATB

 

[j0e_bl0ggs]

Yes!
If you don't know the speed of your rounds how will you accurately, or maybe I should say more accurately, calculate or have an indication you are working within safe pressures? I would also recommend a reloading program (e.g. Quickload), not completely necessary but a great help in addition to reloading manuals (up to date ones as well).
There may be other views but this is the one I work to.
​ATB

Chrono will tell you nothing about 'safe pressures'.

 

[enfieldspares]

In one sense no it is not a necessity. On the other it is if you are loading cartridges that are borderline legal with their velocities where that is relevant in our law. Think our own .303" and in some bullet weights 6.5x55 and, indeed, .308".

However whilst the loading manuals are nearly always not the same velocity results on paper as in your rifle they are, to within a hundred feet per second near enough. That is certain. So a load quoted as 2,600fps in the book will usually never shoot to less than 2,500fps in any given rifle of standard barrel length of 20" or longer.

The two Proof Houses will test ammunition for you and, moreover, give you the result on their headed paper, if you are concerned that you load is or isn't IN VELOCITY ACHIEVED legal or not.

Personally it is nice to know the velocity but if you are within the charge weight figures given in the manuals you are going to be, as mentioned, within a hundred feet per second of their velocity figures in a rifle or "sensible" barrel length.

 

[dlz90]

Chrono will tell you nothing about 'safe pressures'.

Exactly it will tell you nothing about pressure, to much pressure as we all know is potentially a very dangerous situation, I do not have a chrono and do not feel lost without it, yes it can be handy to calculate muzzle energies ect, but excess pressure will only be found with the tell tale warning signs start at min load and work up in small increments, hard to lift the bolt after firing, flattened primers embossing on the case head are just a few things that will indicate unsafe pressures.

 

[jcampbellsmith]

I use the chronograph to assess the quality of my reloading. Ideally I would like to get a Standard Deviation of less than 10 fps for a given load. I also use it to feed into a ballistics calculator to get my trajectory for target shooting.

In an ideal world I would record the velocity of every shot I fire. In practice, I have probably shot for over 30 years before I even saw a chronograph, let alone observed the velocity of my own rounds.

Regards

​JCS

 

[Dalua]

It's a handy thing to have but as has been pointed out, it tells you nothing about pressure or safety.
Using the measured MV and the bullet data, one can calculate drop at various ranges, which is certainly handy for target-shooting, especially at long range. For taking quarry, though, I feel that one should actually test the rifle/cartridge combination at the various ranges before shooting things.

So, in summary, I have a chrono because I can afford to keep one and I like to see what's going on in numbers.
Could I manage just as well without one - almost certainly yes.

 

[swarovski]

I like having a chrony, ive used mine again recently, had a rifle re barrelled to 6.5 06 and loaded up to sierra accuload, was getting really inconsistant grouping, checked velocities and to my amazement the fps was in excess of 150fps faster than data, never ever had this before, wasnt aware it had been chambered to tight saami spec.all sorted now because of chrony, loads reduced and getting nice groups, will be testing at 1000yds this sunday

 

[lister]

I have a chrony because I mess with air rifles need it to stay legal but it is good for checking hand loads
​cheers lister

 

[tackb]

Chrono will tell you nothing about 'safe pressures'.

Correct , but if your getting much higher velocity than comparable factory for example then it's a good warning sign.

 

[caorach]

I don't have a chrony but have access to one but I've only used it a few times and even then it was more for entertainment than any need to know. Unless you are doing a lot of reloading and a lot of chopping and changing and experimenting then I really think there are a very many better things to spend the cash on. The money would pay for a stalk or two at hinds or does and that would give you more fun than a chrony that you will probably only use once or twice unless you are a reloading "hard nut."

 

[Muir]

Chrono will tell you nothing about 'safe pressures'.

Exactly. Pressure and velocity are independent of each other.
What a chronograph does is put some seriously good or bad truths into the loaders face. If he has been boasting about that "shoots half inch any day" rifle and he finds that his loads have a 160 fps extreme spread and a Standard Deviation of 79 fps he might want to rethink his loads and reevaluate the fliers he has written off to too much coffee or his socks being too tight. On the other hand, he could find just the opposite (tight extreme spread and small standard deviation) and realize that he has done everything right by the load and maybe the 1.2 MOA he isn't happy with is simply not to be gotten past with that component combo.

Two chronographs will tell you the actual ballistic coefficient of the bullet you are using at your location and at that velocity. It will also quickly plot when adding powder is not adding any appreciable velocity, quietly advising you to quit that path. Chronographs are good. Data is good. "Quick Load" is plagued with problems and nothing to base loads from. JMHO~Muir

 

[Border]

Correct , but if your getting much higher velocity than comparable factory for example then it's a good warning sign.

Especially with a barrel considerably shorter than the barrels used for pressure testing. It's also interesting to find out real world figures seen as every barrel is individual and will give different pressure/velocity readings. It`s not an essential bit of kit but adds another level of feedback to factory/homeloads in YOUR rifle.

 

[swarovski]

Hi muir, could you expain how 2 chronys give you bc or how to work it out

 

[deeangeo]

I use the chronograph to assess the quality of my reloading. Ideally I would like to get a Standard Deviation of less than 10 fps for a given load. I also use it to feed into a ballistics calculator to get my trajectory for target shooting.

In an ideal world I would record the velocity of every shot I fire. In practice, I have probably shot for over 30 years before I even saw a chronograph, let alone observed the velocity of my own rounds.

Regards

​JCS

It's a handy thing to have but as has been pointed out, it tells you nothing about pressure or safety.
Using the measured MV and the bullet data, one can calculate drop at various ranges, which is certainly handy for target-shooting, especially at long range. For taking quarry, though, I feel that one should actually test the rifle/cartridge combination at the various ranges before shooting things.

So, in summary, I have a chrono because I can afford to keep one and I like to see what's going on in numbers.
Could I manage just as well without one - almost certainly yes.

It's a useful aid to MV with your loads and helps ​calculate bullet drop (trajectory) at various ranges up to & beyond zero impact point. It's worthwhile checking ones loads MV from time to time, helpful, but not essential.

You should also remember, you will more than likely not be checking under lab. conditions using identical barrel and components, so more often than not your readings will not coincide with what the 'book' says.

Muir sums it up quite neatly too.
ATB & enjoy your Christmas present

 

[big ears]

Thanks for all the feedback.
all of my loads are in the top half of the loading ladder so legality is not an issue. Neither do any show pressure signs. Can I ask do any of the non target shooters use a chrono?
​Would a session on a long range be as informative as a chrono?

 

[j0e_bl0ggs]

Hi muir, could you expain how 2 chronys give you bc or how to work it out

http://www.jbmballistics.com/cgi-bin/jbmbcv-5.1.cgi

 

[JMS906]

No, you do not need a chronograph. They are a 'nice to have' tool but certainly not essential. If your handloads are delivering good accuracy then that tells you that you are within safe limits. As a general rule, the best accuracy is delivered with a velocity a few hundred fps below the maximum (paraphrasing the Hornady manual). If you want to know about your 100, 200 and 300 yard trajectories, shoot at those distances and measure the fall of shot. (To the nitpickers: yes, ideally you would want to shoot at three aligned targets but unfortunately we live in the real world. Additionally, manufacturer's published BCs are often exageratted.)

I have chronographs and also QuickLoad. I took some measurements last year with four different rifles being one 223, two .30-06s, and one 7.62x54R. The rifles were a .223 Sako 75, a .30-06 Sako 75, a .30-06 M1903 Springfield, and a Dragunov. To my surprise, I found that the measured velocities were typically within +/- 20fps of the QuickLoad predicted velocities. In other words, if you have QuickLoad and are using it properly, you don't need to measure your velocities as Ql gives a close approximation.

-JMS

 

[jthyttin]

Exactly. Pressure and velocity are independent of each other.

No they're not, there's very strong correlation.

As said, a chrono is useful in may ways but not essential. If you don't have measured velocity, reliable zero and modern software to calculate drops, I would check the POA/POI in all relevant distances (minimum distance is also relevant in addition to max distance, if you're trying to be very accurate)

 

[Lateral]

Chrono will tell you nothing about 'safe pressures'.

Interesting one, and a statement I would question, depending on how you use a crono, and assuming you you have a certain amount of information to start with.

I've had a load that's been used in a specific rifle for a number of years. It's been super consistent, and very accurate. Then, all of a sudden, a problem developed where the firing pin appeared to be holing the primers, or at least pin sized disks started to block the firing pin hole in the bolt.

The load was reduced until at 95% of the original load the issue stopped. Brass, bullets, powder, & primers all from the same boxes/bottles/batch. Although various types/brands of primer had been tried, just to eliminate a faulty batch.

The new load was put over the crono, and found to be within a few FPS of the original load. Now due to circumstances, I didn't get a chance to put the original load across the crono when it developed the issue, but with hindsight, I'm pretty sure it would have saved me messing around testing other primers, and showed a marked increase in velocity, indicating an increase in pressure.

What do you think ?