Why do I need a chronograph?

[forestswin]

besides that its another fun tool to have.


recent discussions here make me want to buy one - but I need a little more of a nudge

I've read that it gives you another tool to determine the best load for your gun. How exactly?

But I've also read that the highest velocity or even the lowest deviation will not always be the best group.

I'm in it for accuracy and grouping on paper and have only loaded with small increments until I get good groups. I associate the charge directly to size of the group.

I understand the "vertical axis" trajectory from a known initial velocity, that's a simple equation and the online ballistic programs can give you that and I can measure that in "INCHES" on the target for a particular charge weight.

But, I'm pretty sure there's more to it than that.

book and/or article references would be appreciated as much as experience, wisdom and/or opinion

thanks in advance

 

[Titegroups]

After you buy one remember they are bullet magnents. Metric are satisfyimg to numbers people.

 

[OKFC05]

What I use mine for the most is to check speed for a particualr power factor required in competition, and to match a load using a new bullet or powder to the speed or power factor I am accustomed to.

It also is a source of great amusement to see what cartridges will actually produce in real guns.
The people who rely on charts are usually in for a great surprise, and often find their "magic " load is more noise than speed.

For handguns at ranges under 50 yards, reliability and consistency matter much more than the types of things we sweat over in long range rifle loads. Let's face it, are you going to notice another 1/4 degree of dispersion in normal pistol shooting?

 

[rwsmith]

cast bullets

I'm shooting cast bullets now that are limited to 1800 fps. I'd like to know that I'm getting just under that.

 

[Twoboxer]

After firing a round downrange, I have only one piece of info about it . . . POI. A chrono gives me the only other quantifiable piece of info (reasonably) available . . . velocity.

A chrono can eliminate velocity as a factor in the spread of a group, or it may identify why one POI differed from the rest.

In load development, velocities can often be correlated to published load data and it's certainly comforting when they do.

Velocities should also change in a reasonable manner as charge weights increase. When they don't, you have a piece of undeniable data confirming a situation you might not otherwise have noticed . . . until later.

OH! And its a fun new toy

 

[Nevada Ed]

I got along with out one for 40 years..................

but now that I have one, I found out those data figures from the manuals and the fps on the ammo boxes are not quite the same !!

They said, I thought, can you believe....................
Opens your eyes for sure on what is really happening.

Nice to know what a load is doing and the es but I have had wide ES loads of 120 out shoot a ES of 15........... but that is really unimportant for me. The velocity is what I am after.

Most long 6" barrels are pretty easy to find loads with since the es and fps are better with the powder getting close to , if not a 100% burn.

I had a heck of a time with my 1 7/8 inch snub nose at first. Later found powders that would work best and find some accuracy loads but it took me twice as long than with the long 6" barrel.
If you do get one remember................
12 Ga. at 3-4 feet
22 rifle at 6 feet or more.........
pistols at 8-10 feet
rifles at 10 feet or more per muzzle blast.

 

[Electraclyde]

Fun to have and know what your rounds are actually doing. What bullet manufactures say and reality are very different.

 

[venomballistics]

we measure case length,COL,bullet weight, charge weight, neck thickness, sometimes even case weight and primer flash hole size in pursuit of a result.
It only makes sense to actually measure, rather than guess at, the result

 

[Oldherkpilot]

I got my chronograph two years ago and knew immediately that I had wasted a lot of time and components without one! Once you establish the actual muzzle velocity (or 10', anyway), you can use that figure in any of a number of ballistics programs to tell you what the trajectory "should" be. Thence you only have to validate the numbers with live fire, not establish them. No program is perfect, but I have learned a great deal since I blew $109 on my chronograph. Just remember rule number one with a chronograph--Don't shoot the chronograph!
Admit it--If Smith and Wesson made a chronograph you would already own it!

 

[alwslate]

There is a lot more to hand loading than just the size of your groups.
I wouldn't attempt to list all of the advantages of owning a chronograph here. In time you'll make your own list. Consistancy is
important to me, I want to see small extreme spreads. Things like
actual vs loading manual velocities, primer, case and bullet effect,
position sensitivity, factory load quality, or lack of. You'll think of
lots more yourself.

 

[varmint243]

I have a Pact PC2 chronograph
I bout it 15-20 years ago when they first became affordable.
It has sat in a case for most of those years.
It was not the magic key to ultimate accuracy.
It was interesting to me to get the data points for a while.
Then it lost it appeal, because I found there was not a direct translation from chronograph results to accuracy.
I recently used it to check velocity on some pistol loads I had made up.
As others have stated the data listed in the manuals can be pretty far off.

I used a high quality match air pistol to make sure the chronograph was reading consistently and it seems to be.

I think what I would use it for now and haven't yet tested is to help with understanding velocity loss. I want to set it up at the muzzle, 50yds, 100yds, and 200yds, and try to make a more accurate chart of how fast velocity is dropping. I believe this information would help me more accurately predict bullet drop in a long range shot. Corrections would still have to be made for temperature, humidity, altitude, and air density.

Maybe someday when I'm retired, I will have enough time to do the chronograph testing I'd really like to do and it will become interesting to me again.

It dramatically increases the amount of time required for each range visit. You also need to use it when you are the only one on the range.

 

[shocker]

I'd much rather have a pressure measurement than a velocity. I like to measure stuff in general, but a chronograph doesn't excite me enough to pay for one. I just follow the load recommendations in late edition manuals and check poi at 100, 200, 300 yds which tells me all I need to know. Rifle loads of course. Handguns are so variable I wouldn't bother, myself. "About" is good enough.

 

[zeke]

Do a lot of chrongraphing of loads, not for anthing to do with accuracy. A lot to do with safety regarding pressures, especially when working up toward max loads. All barrels/chamberings are different from each other and if your velocity is out of the range expected for your load combination, likely your pressures are too high.

Having and using a chrono taught me about the consequences of bullet set back. When the velocitys were "out of bounds", had to figure out why.

 

[LittleCooner]

If you are looking for accuracy ( which you stated you were) then a chronograph is a necessary tool in the reloading equipment. If that is rifle accuracy and you plan on doing any kind of competition, even just stuff at the local range for bragging rights, then it is a must have for reloading ammo.

ES- Extreme spread - long range accuracy with any thing will depend on a load with a low ES. Think about this - ES of 20 will shoot a lot better than ES of 100 at longer ranges. Bullets drop by the law of gravity and that round running slower will land lower on the target that the fast one.

Tuning your gun. (rifle). the experimenters are now into tuners on their guns. Well you can tune your barrel to the correct vibrations and once you find the "sweet spot" it is usually the same velocity at the end of the barrel, no matter what power, bullet you change to, repeat the velocity for maximum accuracy.( not always, but a bench mark to look for in accuracy at the range).

ES and powder. There are something like 250+ different powders on the market for reloading centerfire ammo. Some of this stuff will always be at the top of the heap for accuracy and there are some that go bang but NEVER produce accuracy in the loads. (surf the net, you will find one brand that is the junk of the power market). You will find VitaViouri (sp?) to be at the top of the heap every time. Try it, heck with the price, it works, all of them. if you are not obtaining a low ES, then that tuned sweet spot of Velocity at the end of the barrel is not working - means larger groups.

Then there is pressure, velocity on what you cartridge is designed to do versus what you are loading.

War Story on past experience that was a shocker - For 22 years I have hunted Whitetails with a 284 Winchester and 95 % of the time with Barnes bullets. Years ago, after having a very pet load worked up, they came out with a coating on the bullets, a blue compound that I forget the makeup. Same bullet, with and without loading, same exact everything. The difference in velocity was an eyeopener. 2850 FPS with the pet uncoated load, the same coated bullet would run 3040 FPS. I would mix them up shooting over the crono, thinking the thing was broke. Well you will only know whats happening with a chronograph.

All barrels are different from one to another, always, and one load running a certain speed does not reproduce in another barrel. Hey, this is a sport and we are having fun. but if you want the smallest holes on paper to show friends, or win a round of drinks at the range, spend that $100-$150 and add it to the equipment. It is a required for the serious accuracy reloader.

 

[LittleCooner]

Another hint on working up accuracy loads - If you ever go around the benchrest crowd, you will hear the term, "tunning out the vertical". Well the wind most of the time is moving that bullet right or left unless its a true tail or head wind. STOP measuring those groups for tuning results - look at the vertical. when you get that barrel tuned with low ES and correct vibrations for velocity, there will be no vertical in the groups. That right -left stuff in the wind moving the bullet and then its all about reading the flags and beating everyone else that day.

 

[tops]

I am amazed at the different velocities from the same loads in different guns. I have found that if I want to know what my gun and load is doing is doing I have to check my gun and load. Shoot the same load in another gun that is supposed to be the same and get a different velocity. People that go by "the book" don't have any idea the velocity. Velocity is important to me so I can figure the energy for different bullet weights and barrel lenghts. Larry

 

[SMSgt]

OP, I'm kind of in your boat. When I have to have degrees in upper-level math and physics to create an accurate load, it will take the fun out of reloading. I merely adjust powder weights/types and COL until the bullets go where I aim. Then I leave things alone. The deer can tell me the results. I've never wondered if the bullet was going 2900 or 2975 fps.

 

[arizona98tj]

While I rarely care if my rifle bullet is doing 2900 or 2975 FPS....without a chronograph, how do you tell when it's only doing 2475 vs. 2975? Just wondering....I was never able to figure that out even though I took some of that upper-level math you were talking about.

 

[SMSgt]

Because it drops off the bottom of the target at 300 yards?

 

[Forrest r]

Interesting!!!!!

I must be the only one who uses a chronograph to test the mechanical abilities of a firearm. I could care less about how fast/slow a reload goes, the target & bullet will tell me everything I need to know.

Consistent ignition in any firearm is critical to accuracy. The only way to truly tell if you are getting consistent ignition with a specific firearm is by testing it with a known lot of ammunition & a chronograph. I live in ne Ohio right on Lake Erie & we have long cold winters here. I usually wait until late January or February to test firearms. The cold brings out the worst in them.

I’ve easily cut groups in ½ in numerous firearms by using a chronograph to test them with. What happens is this, I use a known lot of ammo that has performed well (low consistent SD) in several different firearms. That ammo is tested in a firearm that is known to function properly at the same time as the firearm being tested. If the known firearm has a SD of 8 & the firearm being tested has a SD of 45, there’s a problem.

When this happens I start checking fp’s for burrs or being bent. Check & replace the fp spring, polish the fp, bolt & springs. Polish & moly treat all the moving ignition parts, reshape the fp, or look for the sear or anything else dragging on the fp.

It’s impressive to finish working on a firearm & have it shoot bug holes in targets with the same ammo it could barely get to group before it was tested with a chronograph & a known lot of ammo.

 

[Cdog]

If you load for plinking or average deer hunting, maybe you don't "need" one.

For the low cost of a decent quality chronograph, I sure "enjoy actually knowing" just what my combos are doing.