Why do I need a chronograph?

[JeffsSig]

Ok From all I read not many chronographs are 100% accurate.

Why would I need one?

[JeffsSig]

I guess one can look at like this.

A chronograph is a measuring tool. Right?

A guy cutting firewood doesn't need even a yardstick, but a carpenter needs a good tape measure.

So why are we measuring speed if load A and load B both produce the same end result on the target?

[RED333]

So why are we measuring speed if load A and load B both produce the same end result on the target?

Not true, I reload my own slug that I make, the weight vaires very little that I can tell.

How ever after I went up on the charge just 2 grains my slugs went to be flires.

At 19 grains they would hold a 4" group at 100yrds, at 21 grains I got the flires.

I would like to know if I am picking up any speed to off set the flires.

I know slugs at 100 yrds, who cares, well I do.

12 ga is cheep to reload, make my own slugs, use Green dot powder.

Mostiy I like to know I can do the reload and have something to shoot.

[Guest Lester Weevils]

If my chrony was repeatable but horribly inaccurate-- Maybe I shoot Hornady factory ammo over the horribly inaccurate chrony, and it ought to read 1200 fps but the chrony tells me 900 fps. So if I shoot one of my loads over the chrony and the chrony thinks my load is also 900 fps, then I would know my load is the same velocity as the factory load, even if I don't know the "true velocity".

Which is kinda like "cut to fit" carpentry. If you need to cut a board a certain length to fit between two other boards, its gotta be that certain length to fit regardless of what your ruler tells you. Similarly if you were making a replacement part on a lathe, the acid test is will the part fit? If I measure the "hole" and it measures 101 mm but my caliper has a 2mm error and it is really a 99 mm hole. As long as the caliper is repeatable and I make the part so it measures a little shy of 101 mm as measured by my screwed-up caliper, it will fit where it belongs.

[Dolomite_supafly]

Because there is not a factory load or even reloading data that will match your gun. It also saves ammunition during testing.

If you can go out and shoot at various distances to determine drop then you probably don't need one. But for some of us we can't go spend an afternoon shooting. And for those who can't or don't want to spend an aftermnoon shooting we can figure our or holdovers, at all distances, from firing 5 shots. That is what I use mine for mostly, knowing the holdover at longer ranges than I am able to shoot. And I can save ammunition by using a chronograph rather than shooting a bunch of ammo at longer distances.

I also use it to load to a certain FPS to duplicate factory ammo. I have loaded ammo in the past that I thought was 3,500 FPS. Well when I got my chronograph and shot those loads across it the numbers were actually under 3,200 fps. That is because I used the load data provided and it is for a much longer barrel than I was using.

Dolomite

[peejman]

It's all a matter of how good is good enough? If you're satisfied using factory ammo and getting minute of man accuracy at 200 yds... you probably don't need a chronograph. If you're developing your own hand loads for the next 1000 yd match or think 0.5" groups at 100 yds aren't good enough... you probably need a chronograph.

As to the accuracy and or consistency/repeatability of it... again, it depends on your intended purpose. If you're shooting at 100 yds and calculating drops at 800 yds... accuracy is paramount. If you're working up next season's deer load and never shoot past 75 yds.... consistency is more important than absolute accuracy.

Edited June 27, 2012 by peejman

[Guest Grout]

You only need one if you are concerned about the velocity of your loads.If you are just loading plinking or practice ammo then no point in owning one

[Jonnin]

No measuring device is 100% accurate for anything. A powder scale is not accurate to 1/1000 of a grain, so why would we need that? Well, any measuring device that is "good enough" for the job is just that, good enough, and if you need the data, you buy the device.

You measure velocity because you want to know velocity. That is the only reason to buy a tool that measures velocity. It can be used in many ways from checking your consistency (they all give the same value +- 1% device error or whatever) to calculating ballistics (if you care) and more. If you have to ask why you need it, you probably do not need it! I do not have one, and while curiosity keeps making me want one, I have no need for it.

And finally, the "tool" question. When buying a tool (gadget, whatever) you ask yourself 2 questions:

1) do I need this (if yes, name the specific project it will be used for and why nothing else will do the job)

2) Do I want this (if yes, that is sufficient, but answering "what for" can help you decide).

Mentally doing that prevents buying things you do not need or want, or it does for me.

[mikegideon]

The chrony accuracy debate makes me nuts! Chronographs are simple devices, outside the bells and whistles that get tacked onto them. Quartz timebases are generally accurate and stable. The required accuracy in spacing between the sensors is easy with today's manufacturing tolerances. The name of the game is making the sensors read the bullet pass reliably.

Velocity matters very little at close range. It matters a lot at long range. I use a chrony for the same reasons as Dolomite. If I'm trying to duplicate the performance of a factory load, especially with a wildcat, I need to know the velocity. Most factory ammo velocity is specified with a 24" barrel. Most of my barrels ain't.

[Caster]

If you are brave or foolish enough to step off the beaten path of documented load data, the chronograph is the difference between finding gold and getting part of the receiver stuck in your forehead. The idea of reading brass for pressure signs is as much hocum as anything. You can be deep into dark territory and show NO signs of pressure. The difference there would be loading that on a january morning and shooting those loads out in the sun of a July afternoon.

[mikegideon]

If you are brave or foolish enough to step off the beaten path of documented load data, the chronograph is the difference between finding gold and getting part of the receiver stuck in your forehead. The idea of reading brass for pressure signs is as much hocum as anything. You can be deep into dark territory and show NO signs of pressure. The difference there would be loading that on a january morning and shooting those loads out in the sun of a July afternoon.

You DO have a way with words .