Chronographing

[Frank]

I know a guy who likes to spend all day on a chronograph. He doesn't do a lot of load testing. There is just a batch of one powder and one charge, then another powder and another charge and he looks for which has the lowest velocity variation. :rolleyes: I'm not sold on his technique and told him. But he's got all the expensive toys and that means he doesn't like to listen. For example, he spends $10,000 on a bolt gun, but then primes with his press. I told him to check out the Lee auto prime. Priming is important I told him. He said, "Oh yeah?" I'll have to look into it."

I want to have a better answer for this guy next time. Maybe someone here can tell me how important is the spread? What other factors go into finding the accurate load?

[btroj]

Tell him to get a subscription to Precision Shooting magazine and let him spend even more money. He will also learn what accuracy is, and it doesn't come from a chronograph.

I believe our Felix even graced the cover at one time.

Brad

[JeffinNZ]

Why does it matter? If he is happy let him be.

[Frank]

Jeff in NZ said
Why does it matter? If he is happy let him be.

I don't see the happiness in spending a lot of time and not getting results. But you're right, maybe he is happy.

btroj said
Tell him to get a subscription to Precision Shooting magazine and let him spend even more money.
Oh, he's probably got that. He did mention Handloader magazine's recent issue :confused: about using RL15 with mag primers in a .308. He says the load he has is 44 grns of that powder and it's giving him 2772 fps with a 175 Sierra MK, 25" barrel and a 10 fps spread so that's what he's going to use.

[454PB]

As far as I'm concerned, a chronograph is the second most important tool to have when developing a load, right behind a reloading press.

However, some guys are just "OCD".

[mike in co]

it is a tool........but like most tools some instruction is required. with a lack of instruction bliss can come quite easily.

once someone told him " small sd is good" . he took the small bit of info and never continued his education.

[btroj]

I saw lots of new NRA high-power shooter checking SD for their ammo. I did not see the high masters doing it. The high masters worried about other things that mattered in that arena.
Is it a tool? Yes. Mine has told me lots. But is it the most important tool in load development? Not to me.
I tend to avoid discussions with people like this. It keeps me from injuring my neck from excessive head shaking.

Brad

[runfiverun]

it is a tool,it's good for helping diagnose problems.
i once had some serious vertical stringing that was traced back to extreme spread and was cured by using the chrono.
a small e/s-s/d isn't the end all but having them close don't hurt.

[Frank]

runfiverun said
once had some serious vertical stringing that was traced back to extreme spread and was cured by using the chrono.

Well, when you saw the vertical stringing, you could have just changed to another powder and got to the result shooting at a target. In the time you were testing the new powder, in 15 rounds it could fail. But if you're chronographing that powder, you'e wasting rounds and still don't know that yet.

[geargnasher]

The chronograph is a very valuble tool, but the two most important tools are

1. The Human Brain.

2. Used target paper.

Gear

[Doc Highwall]

Check out my post on modifying dies for cast bullet shooting under reloading equipment I have yet to chronograph any of the new loads just reading the target and paying attention to follow-through on trigger control. Extreme spreads never take into account barrel vibrations and the target never lies.

[44man]

I hate to set up the chronograph! [smilie=s:
I always work for the best accuracy and have many, many loads that I don't even know how fast they are.
Whitworth talks me into using it now and then just to see the velocity, I never seen him worry about the SD's, etc and neither do I.
We also never look for the highest velocities with any gun, only the most accurate loads are interesting.

[Wayne Smith]

use my chronograph when I'm developing new cast boolit loads in unusual calibrers. It tells me when I'm approaching the velocity that I want and expect and confirms or disconfirms that my gun is the same as expected. I don't expect it to help much with accuracy. I see it as basic information and safety information. For example I need to take it to the range next time to see how fast the 32 Keith boolit is going in my 32-20 Remington Mdl 25 with 5 gr Herco behind it. The lowest of one of Phil Sharpe's loads. It's hot, I want to find out how hot.

[S.R.Custom]

Why does it matter? If he is happy let him be.

Jeff's got it. It's his hobby, after all. He's probably got a theory of some sort, and he's on a grand quest to prove it. Instead of trying to impart to him what you know to be true, ask him what he has discovered. You might learn something.

As for a hand vs. press installed primer, as long as the primer is seated correctly, it doesn't matter at all how it got there.

[Rocky Raab]

It sounds like some of you shoot either over the chrono or at targets. Why not do both at the same time? That's all I've ever done.

[Frank]

Doc Highwall said
Extreme spreads never take into account barrel vibrations and the target never lies.

He said finding the lowest spread reduces vertical stringing. I attempted to explain there is more involved, like barrel harmonics and the effect of different powders. I even mentioned mag primers for big pistol calibers, and standard for other, and he just said "hmmm". :?

It's more work to set-up a chronograph, but I guess I can do both for the fun of it.

[fecmech]

I use a chrono mainly to give me an idea as to where I'm at in regards to velocity. I generally do my accuracy testing without a chrono and when I get what I want I then chrono to see what velocity I have. I have had a chronograph for over 30 years so I usually know within about 50 fps where I'm at when I select a load but I just like to record the findings.
I'm not a long range rifle guy but I bet small sd's are very important to them!

[Doc Highwall]

I agree that a chronograph is a valuable tool but like any tool it has to be used properly. The biggest thing it shows is how consistent your load is over time with different weather changes. When I use my chronograph for a particular powder I look for a flat spot in the velocity and then start to play with bullet seating depth only if the target shows that it has grouping potential.

[S.R.Custom]

...He said finding the lowest spread reduces vertical stringing...

And he's right...

Like others have pointed out, the chronograph is a tool. If a particular load shoots wonderfully across the eyes, but sprays on paper, you can be pretty sure the problem lies with the gun and not the load. And there is where we begin to see two schools of thought emerge...

One school is where the guy treats the gun as a constant and begins to fix and tinker with the load until he finds something that the gun "likes."

The other line of reasoning treats the load as the constant --it "should" work, after all-- and our man endeavors to fix the gun itself.

Hard to say which one is best.... Although I have found that if I fix a gun to shoot a load the chronograph likes, I get better accuracy than if I fiddle & compromise the load.

[Doc Highwall]

S.R.Custom, you are right you have to fix the gun, maybe the bedding or torquing of the bedding screws is all it will take. I have run into a problem with vertical stringing that has to do with where I rest the fore end of the rifle on the rest and now I am making a stop to attach to my rest that will have adjustment in it to find the sweet spot like the BPCR shooters with their cross sticks.

[454PB]

Rocky is right, it didn't occur to me that anyone would use a chronograph without a target beyond it.

[Hip's Ax]

Out to 600 yards I do load selection according to group size in the actual position I will use firing the match. For 1000 yard long range I use the chrony to make sure I have sufficient velocity to reach the target then I test for group size.

The other use I have for my chrony is trouble shooting. I have a new rifle right now that gives me flat primers at all charges. The chrony told me my lot of H4350 is just fine and upon further inspection I found my unfired brass is stretching 0.009" on firing. Now I think its the head space and after I shoot my next lot I'll know for sure.

I always figured actually practicing would do me more good than laboring over the reloading bench and the chrony.

[geargnasher]

Rocky is right, it didn't occur to me that anyone would use a chronograph without a target beyond it.

Me neither. I would assume that we want to know what the groups look like first, then see how the velocity data compares.

I've done a lot of troubleshooting without the aid of a chrony, if I get vertical stringing I know that either I have a bedding or rest issue, the boolit is exiting at the wrong place in the vibration cycle, or I have ammunition problems. I try correcting by checking the gun and changing the support locations as has been mentioned, then look to a very slight increase/decrease in powder charge to get the boolit to exit at a different place in the cycle. Failing that, I'll change powder burn rate slightly and work up again. If you get high SD it will cause stringing too. but not always. Gotta look at the big picture, like SR said, don't get stuck on diagnosing one part of the firing platform. And don't forget to factor in the nut behind the trigger.

Gear.

[mike in co]

I always figured actually practicing would do me more good than laboring over the reloading bench and the chrony.

but only perfect practice makes perfect....


just doing the same thing over and over is not necessarily good...


so get a good load...the target and the chrono will confrim that...
and then go prictice...

[cajun shooter]

If you yourself enjoy shooting, reloading, casting and all that goes with them then I would stay away from this guy. It seems that he has already caused you to worry about what he does. The old saying that you can lead a horse to water but can't make him drink is very true. I have my entire life been one to try and help others. My choice to become a soldier, police officer, firearms instructor has shown that. I am now at 63 and realize that some will accept your offer and most will poke fun at you at you. A lot of people don't like you if you try to help because they think you are being a show off or know it all. Your intentions are good but not well received. I at one time would be sick when I could not get through to help some one out. I finally realized that they will never accept what I have to say and it is best to move on.

[Larry Gibson]

I also concur with JeffinNZ, if the guy is happy doing that then let him be happy. I know lots of guys who chase SD/ES all the time and they are happiest when doing it. The chronograph is a very valuable tool to most who use it. If you shoot at just one range or 3 ranges in a match you can just pay attention to the groups and be fine. Best to use the longest range however as what seemingly shoots well at close range many times doesn't shoot well at distance. With the use of a chronograph a load with a compatable bullet matched to the twist for the purpose that has a small SD and ES and groups well at a minimum closer range of 100 yards will almost invariably shoot well out at longer ranges.

Thus with the chronograph less time and compnants are spent developing loads. This is why you don't see too many master level shooters tediously going through every possible combination of bullets, powders, primers, etc. developing loads. They already know which componants and loads shoot the best. They also know a .1" better group today does not mean the same will happen tomorrow. They go with known componants and loads that shoot well in all such match rifles at the expected velocities they need for match success. Match success comes with consistent loads and a very small chronographed sample tells them if the load is correct.

A chronograph can also keep a reloader out of pressure problems. No, the chronograph does not measure pressure. Let's say you are developing a load with a certain powder/bullet combination and the books say XX gr is max at such and such fps. With 2 gr less powder you get that fps the chronograph is indication you are near the same pressure as the books (manuals) load. Then at 1 gr more powder but still 1 gr less than the max listed by the books you get obvious pressure signs like a little hard bolt lift and slight ejector marking on the case head. That really is telling you that you are getting into higher pressures and should back off even though the load is still under the listed maximum according to the manuals. The chronograph told you first and there was no reall need to push it with that 1 gr extra. Now, if the SD and ES were reasonble and in relation to each other and the group was good then load up 20 more rounds of that load and shoot them at say 200/300 yards for group.

If the groups are linear and still good for the range then you've a good load and it's time to shoot or go hunting instead of load development. That's what the big boys do; once an acceptable load is found they shoot instead of chase another .1" off the group or chase a smaller SD/ES. The bench rest crowd is another story though and they are very happy doing what they do.......

Larry Gibson

[Frank]

Actually, I don't have a problem with him using the chronograph. It was more of a question of technique. He doesn't do things logically. He see's one guy using one, so he has to get one and uses it. He will give you readings and a basic description of what it's good for, but there is no overall analysis. You can verify that by askiing questions.