Chronographs

[Axis II]

Was asked yesterday if I wanted to go in a chronograph with a shooting buddy. We both shoot long range varmints together (300-500yards) amature pistol competitions at local clubs and I really want to try some of the rifle shoots out to 1k yards. I have seen posts on here about ED, SD, and a few other things and haven't a clue what any of it means. Upon doing some google reading on the topic I saw comments about a chrono can help you find a good load for longer ranges. Well if I am shooting half MOA at 100yards why would it not shoot well at say 500yards? Other than velocity what is a chronograph going to tell me?

Rifle gets zero at 100yards and if the handload produces good groups then we shoot it out to 300-500yards and so long as we can keep 5 shots in a woodchuck we call it good. Handgun loads get checked for function and accuracy resting the handgun on a sand bag. Hunting loads get checked at 100yards and if it produces a good group we call it good.

 

[Nasty Canasta]

They aren't necessary but the data they provide can show how consistent you loading is & once you know the fps it can help calculate your bullets path for long distance shooting. I find it adds to my overall knowledge of what my handloads are actually doing & like having one.

 

[FROGO207]

I don't shoot long ranges but finding a wide node where the accuracy stays good with one propellant can often translate to one at the same speed with another similar type if you can measure them. I also find that charge amounts can vary some and velocity remains somewhat constant. Then you pick the middle of the node if the whole thing is accurate. It is just another tool that gives you info on pressure without expensive equipment as well as speed to help calculate balistics.

 

[Axis II]

They aren't necessary but the data they provide can show how consistent you loading is & once you know the fps it can help calculate your bullets path for long distance shooting. I find it adds to my overall knowledge of what my handloads are actually doing & like having one.

I don't shoot long ranges but finding a wide node where the accuracy stays good with one propellant can often translate to one at the same speed with another similar type if you can measure them. I also find that charge amounts can vary some and velocity remains somewhat constant. Then you pick the middle of the node if the whole thing is accurate. It is just another tool that gives you info on pressure without expensive equipment as well as speed to help calculate balistics.

Every once in awhile I will try for a 5 shot group and 3-4 will stack in the same hole or at least touching and one will be 1/2'' away. Since I have good loads for my rifle should I start over and test each one?

 

[Hugger-4641]

Just because a bullet groups tight at 100yds or 300yds does not mean it will still be stable at 500yds. A chronograph won't solve this, but it may help you determine if your load is too slow or inconsistent.

 

[FROGO207]

Well when components come back you could do some testing. I always look for nodes when working up loads. It is more important with rifle IMO. There are usually two accuracy nodes and I usually find the lowest one is the widest and therefore gives the best accuracy. I strive to use the center of that to load by volume for most consistency.

 

[twarr1]

A radar type chronograph will give you velocity down range.

 

[Axis II]

Well when components come back you could do some testing. I always look for nodes when working up loads. It is more important with rifle IMO. There are usually two accuracy nodes and I usually find the lowest one is the widest and therefore gives the best accuracy. I strive to use the center of that to load by volume for most consistency.

Now when you say node are you meaning where say 5 shots has the same velocity or accuracy?

 

[Blue68f100]

A node is a section on the velocity vs powder charge curve where the velocity flattens out even with a powder charge increase. Then it picks up again, not like a max load. This gives you a window for which to load too for more consistent velocity, low ES & SD's. There is also barrel harmonics in which the barrel will compensate for small changes in velocity. When these 2 come together you have a load that will preform in all conditions.

 

[FROGO207]

Now when you say node are you meaning where say 5 shots has the same velocity or accuracy?

All the same accuracy. The velocity will change a small amount but point of impact will stay close to the same. The further the distance the more the groups open up though usually. Blue68F100 expanded on things for you.

 

[Axis II]

Going to setup the chrono tomorrow and send some rounds down range. What velocity do you strive for in say a 223rem bolt action?

 

[JFrank]

Going to setup the chrono tomorrow and send some rounds down range. What velocity do you strive for in say a 223rem bolt action?

Others data won’t do you near as much good as your own, if you get my drift.. as an overview look for consistency in fps which directly correlates to combustion, ignition, loading practices and scale consistencies.