ordered new chronograph, now what

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by 243yote, Aug 25, 2009.

  1. 243yote

    243yote Well-Known Member

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    finally ordered a chronograph. i have a load worked up but i finally get to see what is really happening. what is the standard way to set up and what valuable info should i be looking for? any help would be grateful.:rolleyes:
     
  2. Russ Hatch

    Russ Hatch Well-Known Member

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    !. Read the instruction book.
    2. set up on sturdy tri-pod, 10 to 15 feet from muzzle or follow the directions recommendations.
    3. Check and make sure you are shooting through the sensor area and above the sensors. Don't ask how I know this, LOL.
    4.Save your readings and compare speeds, es, and SD. These will help you to pick out loads. You compare readings to groups and find the one that meets your requirements, velocity, group size , sd ,es, or all of the above.
    The chrono will tell you when you are reaching the point of diminishing returns when you are increasing the powder charge. If an increase in powder only gives you a small increase in velocity you are getting close to that point.

    There are many other things that a chrono can tell you about your loads when the readings are compared to the targets. You just have to devise a way to keep track of the groups vs the chrono readings. I use a old Redfield target with a large center diamond and 4 smaller ones, I also have a smaller copy of it that I number the diamonds on as I shoot my groups. It works for me.

    Enjoy that new chrono.:D
    Russ
     

  3. 243yote

    243yote Well-Known Member

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    Thanks for replying. I have a load worked up just by group size now. Does the fps coralate to the size of my groups? To clear up my question with my grooup size being good, my max veloc for my particular load and gun is reached?:rolleyes:
     
  4. Russ Hatch

    Russ Hatch Well-Known Member

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    Not neccesarily, In my experience the best grouping load is not usually the max velocity load. There are usually two or more vibration nodes for each barrel load combination that group good. Sometimes you can reach the higher velocity node that gives good grouping before exceeding the max load for your rifle. If I can't reach that node without high presure signs I back my load down to the next lower node and live with the velocity. There is not usually that much difference in the velocity. With that being said I will also try different powders and bullets in different combination to get the best accruacy and the highest velocity. This is where a chrono comes in very handy. If a given load of a different powder does not give me a higher velocity than my standard load does there is no reason to pursue that powder bullet combination. In my 7mm Mauser ww760 gives me good accuracy with Berger 168 grain vld bullets at 2550 fps but I get slightly better accuracy with Hornady 160 grain bullets and RL 19 at 2300 fps. The difference is .2 inches avg at 100yds. The avg is over 30 3 shot groups, .3xx avg for the Hornady bullets and . 5xx or below for the Bergers. I shoot the Berger load when hunting because of the velocity difference..
     
  5. 243yote

    243yote Well-Known Member

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    So the " Node" is the rifle/ barrel combo sweet spot? Does the node change for different bullet/powder combo for your gun? Would i see a simaliarity in fps for a different bullet type of the same weight? Thanks again for the info.:rolleyes:
     
  6. Russ Hatch

    Russ Hatch Well-Known Member

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    Now your getting into internal ballistics where I'm a long way from an expert. Some argue one way and others argue another. Google "rifle barrel harmonics " and you will find a lot of interesting reading. Here is just one to start you out.RSI - Barrel Harmonics

    While bullets of the same weight and speed should be comparable there are a lot of other factors that have a lot to do with it. Each barrel is a law unto itself. You just have to find the best combo. How far do you go in your search? How much of your barrel do you shoot out in your search? Only you can answer these questions. If I'm working with a benchrest rifle I would go a lot further looking for the right combo than I will on a hunting rifle.
     
  7. 243yote

    243yote Well-Known Member

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    Thanks for info ,good article. So what can i see from different powders of different burn rates on a chronograph for the same rifle?:rolleyes:
     
  8. Russ Hatch

    Russ Hatch Well-Known Member

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    Basicaly you will be able to tell which powder will give you the highest velocity with the same bullet. The manuals will give you different speeds for the same bullet shape and powder. This is because of different test conditions and barrel lengths.
    With the cronograph you will have the info from your barrel and be able to utilize specific information for you specific gun instead of guessing What the speed of a given bullet and powder combination is.
     
  9. dariuszczyszczon

    dariuszczyszczon Well-Known Member

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    So here is my dilema just bopught a new chroy chornograph to measure my 7 rem mag shot 3 rounds and it showed 3 different fps speeds so now im confused can anyone tell me why 2903,2920,2892 is this normal or is something wrong?
     
  10. jmason

    jmason Well-Known Member

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    I'd open a new post w/ your dilemma so you get a better response. That isn't a load I'd recommend using for LR.:)
     
  11. 243yote

    243yote Well-Known Member

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    So is there a coralation between fps and different powders? will my gun shoot the same with different powders if i keep them in them at the same speed if I only change the powder and everything else stays them same? Will the same powder shoot good in fall , winter and spring with the same load? Hard finding powder i wanted to use but found a powder that is in good supply and most loading manuals do not have info for it. What powder you ask? Western powders. I have been using xterminator for .223 and hunter powder for my .243. I have been getting good results with the powder. i live in a small town and only get to the big city once in awhile. so when I am in the city in check to see what is available. New to long range shooting and got bit by the bug. Made a 200 yd shot on a coyote last week with my .243 awesome. One shot one kill . Any info is helpful and thank you for your info.:)
     
  12. jmason

    jmason Well-Known Member

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    "So is there a coralation between fps and different powders?" YES

    "will my gun shoot the same with different powders if i keep them in them at the same speed if I only change the powder and everything else stays them same? "

    Doubtful

    "Will the same powder shoot good in fall , winter and spring with the same load?"

    Maybe, you'll have to test and see
     
  13. 243yote

    243yote Well-Known Member

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    So what kind of powder works good for a, all around powder? Good powder or the powder you want is hard to find now a days. So what would be a good compromise? I have a question also it seems to me alot of people seem to use IMR powder why? I have not used the stuff yet ?:)
     
  14. jmason

    jmason Well-Known Member

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    "So what kind of powder works good for a, all around powder?" It depends on the cartridges your shooting. I haven't really loaded for a 223 or 243 so I can't say. If you post this question in a new thread in the reloading section you'll get a better answer. I'm certain there are lots of members having good luck with the 223 and 243.

    "Good powder or the powder you want is hard to find now a days. So what would be a good compromise?" I would post which chamberings you asking about with this question in the reloading section.

    "I have a question also it seems to me alot of people seem to use IMR powder why? I have not used the stuff yet ?:)" Most likely they tested it in their gun and like the results. There's no magic powder and the no free lunch. You have try them and see how they do, but posting a new thread specific to powders for the guns your working with will help make your lunch less expensive.