1. Attention: We have put together a thread with tips and a tutorial video to help with using the new software. Please take a moment to check out the thread here: Trapshooters.com Tutorial & Help Video.
    Dismiss Notice

Chronogragh Consistancy, factory vs reloads?

Discussion in 'Shooting Related Threads' started by yendor12, Jan 15, 2012.

Thread Status:
Not open for further replies.
  1. yendor12

    yendor12 Member

    Joined:
    Oct 29, 2008
    Messages:
    154
    Two scenarios. First is using factory shells from remington. What is on the box is not what they chronograph at.
    Second is my test shells measured all exactly the same never come close to the same speed.

    I use Rem Sts and Hdcp hulls. Factory 1200fps shells chronographed at 1155-1175
    while 1235 factory hdcp shells were at 1190-1210. I have used different lots over the years and with the same results. Do you think this is correct?

    Secondly using the same chronograph I have been using 21.5 green dot.(measured each test load) trying to match the 1235 load. Each shell is perfectly measured for this test.
    My consistancy is never close with the green dot loads, I vary from 1180 up to 1268. I believe this is to much difference.

    Does anyone have this problem? on either scenario? Maybe the cold weather is a factor even though all the shells are warm???

    Rod from Ohio
     
  2. Auctioneer

    Auctioneer Well-Known Member

    Joined:
    Jul 5, 2009
    Messages:
    4,964
    One put a good strong spotlight over your chronogragh. Some work with shadow's.

    I tested STS factory shells and they were all over the place with FPS. Its just the way they are. I even complained to Rem and they told me to send them the shells in question. I did and they said they tested the shells and they said they were in the standards they wanted them to be in.

    As for shells saying they should be 1250 FPS and they turn out to be less. That is called lawyers and insurance. They would rather have the shells shot less then the marked speed and be safe then have them go over the marked speed and have a legal problem because they damnaged a gun or hurt someone.
     
  3. crusha

    crusha TS Member

    Joined:
    Jan 29, 1998
    Messages:
    5,762
    Do you have a lot of experience using chronographs, or is this your first-time exposure to measuring things?



    Not in any way saying you did anything wrong...just that people are usually more surprised than not, once they actually start measuring things themselves.
     
  4. yendor12

    yendor12 Member

    Joined:
    Oct 29, 2008
    Messages:
    154
    I can't say I am an expert. I have only used one for the last 4 years trying to be more competitive.
    Overall I have reloaded for many years.

    Light may be a problem, do you think brighter light gives less accurate results or less light?
    Rod
     
  5. lance howard

    lance howard Member

    Joined:
    Mar 29, 2009
    Messages:
    65
    Rod, I have chronographed many loads over the years. I have found weather does make a difference in the results and powders and primers from lot to lot as well as wads also make a difference in your results. I use an Oehler 35 chrongraph with the middle proof screen set up with a printer. I also have a much cheaper chronograph that gives generally higher readings. Real cold weather always makes for a larger shot to shot variance in my tests. Real warm weather usually means higher velocities with the same loads. I use STS lt handicap loads for most of my handicap shooting. They generally chronograph in mild weather at 1190 - 1219. My reloads using green dot, Downrange fig 8 wads, Fiocci primer average from 1177-1208. I got the velocities up to the factory averages but with more powder. I sent those to be pressure tested and will report the results here when I get the tests back. I also sent some Wal-Mart loads and Estates that I reload to be pressure tested. The average 1 oz reload that I put together with DRso wads and 700x runs in the 1155-1177 range. That load is with the WW209 primer, the Nobles vary much more and are no good in the winter. The most consistent velocities in STS cases have been with the Fiocci primer. The Fed 209A produces higher pressure and more velocity variance than the Fiocci. After 3-4 reloads the velocities drop and the variance in velocity is much greater I think becasue the case mouths are getting tired. I chronographed some cases that I loaded ten times and got velocity averages in the 1152-1204 range with the same loads that produced better averages when the cases were newer. That is not a surprise. The real crazy variances in load performance have been with the cheap cases after 2-3 reloads. Not worth it. Stay safe and keep loading. Lance Howard
     
  6. build4u

    build4u Member

    Joined:
    Feb 16, 2007
    Messages:
    129
    I used to be a competetive pistol shooter in a sport where our bullets had to go a specified min. velocity based on bullet weight or our target scoring values was lowered. I used a chonograph a lot indoors and outside. Usually if lighting is an issue you get a really way off reading, error, or most the time no reading at all. I used a PACT and Competetion Electronics. When traveling around the country we would get various readings based on elevation, temperature etc. I was always told that the factory loads were shot in fixed breach test barrels that were longer etc. to vary the readings. Barrel to barrel from the same manufacturer on my main gun and back up I would get different reading even though I built a matching pair. Have you ever chronograph shotshell reloads to see how close to the recipe info? I have never tried but my Clays load recipe feels softer than than the matching Winchester factory load. David
     
  7. build4u

    build4u Member

    Joined:
    Feb 16, 2007
    Messages:
    129
    I forgot to mention I spoke to Hodgon the other day on a reducing a lighter load of International for a load for my children. They advised to watch for a dirty burn when working down especially in colder weather.
     
    Lou Tenant thanked this.
  8. Avaldes

    Avaldes Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    1,875
    Location:
    Central Coast of California
    You might do a search on Neil Winston's method for chronographing. He goes into detail about how he sets up the light based chronographs to get the most consistent readings. He compares them against his inductive chronograph, which is what the manufacturers use to measure speed.

    Part of the problem is that we are reading a whole bunch of little projectiles instead of just one bullet. The daylight chrono's are MUCH better at reading a single body passing thru them...even in low light.
     
  9. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,529
    Location:
    NE USA
    Factories generally hold their shotshell ammo to standards of ±100 fps and ±1000 psi of advertised specs. This from an American powder maker and an American wad manufacturer.

    Keller
     
    Lou Tenant thanked this.
  10. Avaldes

    Avaldes Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    1,875
    Location:
    Central Coast of California
    I'll make it easy:

    http://www.claytargettesting.com/study2/pages/study2.html
     
  11. BigM-Perazzi

    BigM-Perazzi Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    8,542
    Location:
    HELL, MICHIGAN
  12. Johnny

    Johnny Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    2,962
    Do not "put a good strong spotlight over your chronogragh." They work best in light shade.

    You will never get the same velocities listed by the factory. Using the published velocities in reloading manuals will get you close enough.
     
  13. 1240fps

    1240fps TS Member

    Joined:
    Apr 25, 2009
    Messages:
    23
    Location:
    Northern Il.
    Here's what works for me. I use two or three "Factory loads" usually Remington 2 3/4 1oz @ 1185fps, Fed SC177 1oz @ 1240 fps and sometimes a 1oz Nitro @ 1290fps to validate that days chronographing session.

    I move closer or farther from my Oehler 35P first screen to test and recorded the speeds of the factory loads. When I comfortable that all is well and within 10 to 15 fps of advertised factory speed I test my reloads.

    I only want to know where I'm at in relationships the the control ammo. This has served me well for 20 years. Good Shooting, Bob
     
  14. whiz white

    whiz white Strong Supporter of Trapshooting Banned

    Joined:
    Jan 29, 1998
    Messages:
    4,771
    Location:
    Rapid City SD
    I have chronographed brand new Remington Nitro's and Federal paper extra-lites at the testing facility at H-S Precision here. They make and test test barrels for ammo manufacturers, as well as sell their own custom rifles, and sniper rifles.

    I saw similar results as the original poster here. In fact, the standard deviation in the lots I tested had higher values than some of my tested reloads.

    H-S has an enormous commercial Oehler Ballistic Chronograph as they also chronograph loads used in testing armor plate for the State Department. This is a pretty serious business, so their equipment is top notch.

    I, however, use the Chrony system, but I am not trying to check factory loads. All I want to do is compare my particular reloads to factory shells that I like. I like the Federal paper extra-lite 8½, and the Nitro 27 8's and 7½. This is what BigM-Perazzi addressed above.

    Some say you have to be a certain distance from the chronograph, ambient light conditions, and then there's the debate about shot string and average velocities in that range, etc., etc. I am a mathematician and I do not get all worked up about all these external properties. As BigM- Perazzi stated above, we are simply using the chronograph to arrive at some comparative relationship between liked factory ammo and our reloads.

    Some guys get anal about exact powder drop grains, exact pellet counts, when, in my sole opinion, these really are nothing more that time-wasters. I'd worry more about relative humidity, barometeric pressure, and shell temps, than exactness.

    It reminds me of the local Coca Cola bottling plant. It is owned by my best friend back in high school. You could stand at the inspection station when they were bottling Coke and see slight variances in how full each bottle was. Nothing is exact.

    WW
     
  15. build4u

    build4u Member

    Joined:
    Feb 16, 2007
    Messages:
    129
    it is for sure a bunch of bbs however ten feet from the chrono and 18 inch apart sky screens does not let the shot spread or string out enough to get an unrealistic reading. it will read the shadow of the leading edge of the shot column to shadow of leading edge of the shot column at the second screen.
     
  16. AEP

    AEP Member

    Joined:
    May 6, 2009
    Messages:
    166
    I've had a Ohler Chronograph since the mid-70's. I've spent many hours/days chrono different loads.

    Your load has a large spread. I'll bet your pressures are low and that's whats causing the velocity spread. Load up 20 shells. All the same. Try setting 10 shells outside at least 1 hour before you chrono them. Hopefully the outside air temp is around 40-45 degrees. Take the other 10 shells and keep them at 75 degrees. You will be amazed at the difference. I was.

    I remember when 800X came out and everybody, around here, was using it. Everybody loved it. I chronographed a bunch and found in cold weather they were terrible, and so was Green Dot. I'm talking about loads that were supposed to be loaded to 1,200 fps.

    American Select is another powder that in my opinion doesn't work all that great in cold weather.

    For all around it's hard to beat Red Dot, Clays, 700X, or any of the fast burning powders.

    Good luck,
    Andy
     
  17. Johnny

    Johnny Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    2,962
    build4u, the leading pellets will be faster that than the rest. That's why the factories use inductive chronograph to eliminate reading the lead pellets. And that is one reason your chronograph won't match factories velocities.
     
Thread Status:
Not open for further replies.