Chronograph for reloading

[Brbecker]

[Meety Peety]

Chronograph data is not the end-all be-all of safety (Always look for signs of pressure) but you are correct, a chronograph is a tool you can use to help you monitor your loads and make sure your velocities are within a safe range. It will also show you your extreme spread, standard deviation, etc.

[MrElectric03]

I have loaded for about eight years now and still don't have a chronograph. I have mostly loaded plinking rounds. Now I'm getting into long range rifle for hunting and have been looking for one. I'll be buying one soon and eventually I'll get a lab radar. I'm a buy once cry once kinda guy.

[garyngwind]

Extractor marks or swipes, flattened or pierced primers,

hi Red, "extractor marks" means those deep scratches done by the extractor ONTO THE RIM of base?

something like this?


I suppose this only apply to semi auto gas guns?

and what you mean by Flatten primers? I know if a primer is "unseated" and pop out of the pocket, that means it is a over pressured.

[Fizz]

A chronograph won't help you with load safety. It will help you make sure your loads are consistent and isolate variables such as position sensitivity, environmental temperature, crimp, effect of primer changes, different brass (usually because they crimp differently or snug a given projectile more/less), etc.

The velocities in your reloading manuals are specific test barrels. Unless you use the same barrel and environmental factors they did your chrono results will be meaningless as far as pressures are concerned. Even if you use a similar length barrel, you have no idea what rifling pattern they use, tightness of their chamber, rifling tighter or looser than your barrel, etc.

For example. If the manual publishes that a load through their 6 inch test barrel developed 1000fps and xxxxxx PSI/CUP and you shoot out of a 3 inch, you may be OVERpressure chasing that 1000FPS target because you'll be loading hotter. However, you're generally fine as long as you don't try to exceed the max load trying to chase the same velocity, so long as you work up and don't observe pressure signs prior to getting there.

[OpenSightsOnly]

hi Red, "extractor marks" means those deep scratches done by the extractor ONTO THE RIM of base?

I suppose this only apply to semi auto gas guns?

and what you mean by Flatten primers? I know if a primer is "unseated" and pop out of the pocket, that means it is a over pressured.

BTW, if you get those half-moon ejector marks on the brass rim and you have a carbine, your gas system may not be properly timed.

Check this out (very good read since it covers how the gas system works and brass over pressure signs) from AR15Barrels - http://www.ar15barrels.com/prod/operation.shtml

[tonyjr]

I bought mine on sale and sold for more a month later .
I bought for checking different powders , bullet types and regular
vs mag primers .
Not enough difference to bother [ mainly pistols then ]
More important to me was recoil and how clean the powder was .
But I / we just punch paper now .
Not knowing what you have , I would suggest a few reloading manuals .

[not-fishing]

Downside I've found for rifles is that Accuracy goes down as speed goes up.

There is a sweet spot to each rifle. Find the sweet spot and load to that. For my rifles it's always been closer to factory loads and super speedy.

The only thing I really use my chrono for is competitive pistol loads because you want to be close to minimum power for recoil control in action shooting with a consistent trajectory. For the vast majority of handguns the shooters inability far exceed a large group that a load may print.

[SCDHoliday]

If power factor or ballistic calculations are important to you the chronograph is a valuable tool. For plinking rounds I wouldn't waste the money and would stick to published load data while looking for pressure signs.

[rm1911]

Downside I've found for rifles is that Accuracy goes down as speed goes up.

There is a sweet spot to each rifle. Find the sweet spot and load to that. For my rifles it's always been closer to factory loads and super speedy.

The only thing I really use my chrono for is competitive pistol loads because you want to be close to minimum power for recoil control in action shooting with a consistent trajectory. For the vast majority of handguns the shooters inability far exceed a large group that a load may print.

[sammass]

So... with a relatively new wildcat - 224 Valkyrie - and very little reloading data history available, is the reloader pretty well stuck with the published information? If one were attempting to place max kinetic energy with accuracy at a specific distance, what would be the most reasonable path? It would also seem a chrono would be of value in laddering up your reloads. I don't want to create catastrophic failures, but also nice to know the perimeters of the published data. Thanks.

[SCDHoliday]

So... with a relatively new wildcat - 224 Valkyrie - and very little reloading data history available, is the reloader pretty well stuck with the published information? If one were attempting to place max kinetic energy with accuracy at a specific distance, what would be the most reasonable path? It would also seem a chrono would be of value in laddering up your reloads. I don't want to create catastrophic failures, but also nice to know the perimeters of the published data. Thanks.

Safe loads can be made without a chronograph, reading pressure signs on the brass & gun will guide you. For long distance shooting where ballistic programs are used you will need a chronograph to verify the velocity of the rounds coming out of your specific rifle.

[LynnJr]

With a chronograph you can map out your loads.
That means a xxx change in powder produces yyy change in velocity.
If your getting 50fps per grain of powder increase and it starts climbing your near max pressure.
So if your load is 40 grains and your velocity is 3000 FPS and you increase the powder to 41 grains and get 3100fps your into the high pressure region.
Your target will show small incremental amounts of climbing on the target and when you get near pressure those increments will open up considerably.