Lot speeds are they by design or luck of the draw

Discussion in 'Rimfire & Smallbore' started by Hi-NV Shooter, Sep 22, 2019.

  1. Hi-NV Shooter

    Hi-NV Shooter

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    Just as the title says, do you think ammo makers purposely create different speeds for any given match ammo they make. and I am talking .22 lr
    I do believe Eley has recently stop putting this information on the lots

    Lee
     
  2. spclark

    spclark Gold $$ Contributor

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    It’s gonna vary so much depending on the equipment it’s fired in, they may just be trying to reduce the ‘grouse factor’ from customers who are disappointed they’re not seeing the velocities printed on the packaging.

    Being manufactured products, rimfire ammunition’s got any number of variables that affect ultimate velocities from batch to batch.

    I’m glad the manufacturers can get as consistent a product out to us as they do!

    Even if I can’t afford to shoot the best of the best.
     
  3. justinp61

    justinp61

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    I always figured (probably wrong) that they had a "target range" for velocity to fall into. I also always figured the bullet design determined the "velocity range" for a particular line.

    I work in a pretty large chemical plant and through the steps of our processes testing is done to maintain the quality of our products. If it falls out of the accepted range at any point adjustments have to be made. We know when we start any product barring some major failure the finished product is going be in the "target Range" of our requirements.
     
  4. linekin

    linekin Silver $$ Contributor

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    Lee, if I understand the question right I don’t think they would bother trying to make a certain speed of ammo. Especially in single digit increments.
    I think they know to an extent how to stay within a 30FPS window.
    Then gets tested & marked accordingly.
    Funny thing about superstitions but I don’t test Eley over a written speed of 1062. And I know I’m missing out on a boatload of great shooting lots.
    With Lapua I won’t buy anything other than a 27-lot. Go figure!
    Keith
     
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  5. USMCDOC

    USMCDOC

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    seems like i like 327 it's a nice number.. just ask Chevy
     
  6. Tim s

    Tim s

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    I have wondered but never worried about this.
    I suspect that when they do setups on a machine or batch of components in Lapua’s case then everything gets some form of recalibration and based on how little there is of powder it has got to be a pretty small variance for a few fps change.
    With ELEY it has always been machine driven, nobody I ever heard, chases velocity and if it’s good in my guns, over the years, it could have been anywhere from low 50’s to high 60’s, with Lapua all 70’s.
    So ultimately I come down on the production variance over lot production but, hell, it could very well be mix it up a bit for the customers.
    Anybody gets motivated, call Paul Tolvsted at KSS since it is an ELEY inc. operation these days.
    Nobody I ever heard of ever chased certain speeds over other considerations anyway.
     
  7. linekin

    linekin Silver $$ Contributor

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    Have any of you ever chrono'd your ammo to see what there was for any variance? I don't own one but have always been curious as to what some of my better lots would have shown.

    Keith
     
  8. Hi-NV Shooter

    Hi-NV Shooter

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    Bill Jenkins took that engine to a lot of 1st place finishes good ole 331 SB

    Lee
     
  9. Bill K

    Bill K Silver $$ Contributor

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    If you think about it, you could buy a given box of 22 lr ammunition and sit down and shoot it in your rifle and have a partner shoot it in theirs and you will find the FPS would not be the same.
    So this is going to hold true with any ammo, no matter the lot #, to many variables in barrels/chambers, etc. Bill K
     
  10. Hi-NV Shooter

    Hi-NV Shooter

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    Keith,

    IMO since you can not alter the load on a .22lr it doesn't matter knowing the speed. I mean if you can score 250/2500 does it matter if it is 1040 or 1080 fps. by the way this thread pertains to RFBR since , with the exception of sporters, tuners are used to time the barrel for the different speeds.
    kevin Nevius recently made comment that he doesn't believe speed plays a part in vertical dispersion, his own findings, I believe he said, his chrono testing it didn't show a correlation.
    I don't think any RFBR competitor will blindly buy lots based on speed, they just test it and see what they get. for awhile, I thought 327-328mps in Lapua was what my rifle's liked best, however you know I been fooling with ultra-lite tuners and now my rifles will shoot 326-330, why, IMO I have altered the barrel timing. I don't want to use the PC word here, but less just say it has adjusted for different speeds.
    but getting back to the question, I don't believe ammo makers intentionally set out to make any lot batch a certain speed, if they did or even could then they would look back at their records and see which speeds sold the most and make the majority that speed.

    Lee
     
  11. linekin

    linekin Silver $$ Contributor

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    Lee, agreed it doesn't matter if its capable of easy 250's/2500's it great ammo.
    I guess my chrono question was if there was less of a variance with it as opposed to lesser shooting lots. Just curious.

    Keith
     
  12. Tim s

    Tim s

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    Yes, with a chrono & a Labradar. The Absolute best ammo I have shows an ES with a couple barrels, 3-5 fps spread, lots of it is mid teens.
     
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  13. Tim s

    Tim s

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    FWIW, my tuner gets set......there it stays. Never have tuned for speed, have played with tune between ELEY & Lapua but I suspect that may lube related.
    Remember IR sporters cannot be retuned and great ones shoot hot, cold, and everywhere in between, my personal heavy guns are OK with anything over 50 deg to 90.
    Nobody I shoot with on a regular basis does either and that includes a few IR gold level HOF guys.
     
  14. Hi-NV Shooter

    Hi-NV Shooter

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    My rifles are the same, once I find a setting, may take several ranges session I don't need to change the setting. your mentioning of sporters is what I try and achieve when tuning, as you stated they can't be adjusted and will shoot in any condition, I have a rifle that does that, a Anschutz setup for unlimited from the 30's to 100+ I do not have to change the setting been set the same for nearly 3 years now.

    Lee
     
  15. Hi-NV Shooter

    Hi-NV Shooter

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    Keith,

    I have never chrono ammo, and wondered the same thing.

    Lee
     
  16. linekin

    linekin Silver $$ Contributor

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    Thanks Tim. Don't know if it correlates to anything accuracy wise but can't hurt.
    Seems like there's so many variables to what a chamber likes & why its hit or miss why some lots shoot well & others don't.
    Lee, sorry to have veered a bit of topic. Seemed like a opportune time.

    Keith
     
  17. Hi-NV Shooter

    Hi-NV Shooter

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    Keith, Never need to apologize, any information is useful

    Lee
     
  18. HuskerP7M8

    HuskerP7M8

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    Hi Keith,

    With over 80,000 rds in my ballistic tunnel using a dual chronograph system of my own design that's both paired and calibrated to work together, good match ammo will have a velocity Standard Deviation in the 6 fps +/-1 fps range.


    To get numbers this good, you're forced to use Eley Match/Tenex or Lapua Midas +. I haven't tested enough RWS R50/R100 to verify if they may have the quality control to match Eley/Lapua.

    With that velocity SD, the corresponding velocity Extreme Spreads will range from 30 fps to 42 fps for 50 shot strings. With 25 shot strings like we shoot on a target, V ES's will generally average around the mid to high 20's.

    If you use small samples in your testing (5 or 10 shot strings), it's not possible to quantify the quality of the ammo based on velocity statistics, and in any event, numbers this low won't show up on a typical target because velocity SD/ES isn't close to being the major source of dispersion in RF.

    Remember, these are good stats for "real" match ammo using adequate sample sizes and not some of the crap that may have "Match" stamped on the box.

    Anything much worse than these numbers will degrade target scores and group sizes, as well as being discernibly worse at distances past 50 yds/50 M.

    Do some lots have better velocity stats than other lots? Yes, but in general there's not enough of a difference to fret over.

    That being said, I have come across rare instances with both Eley and Lapua where someone apparently fell asleep on the production line and primer and/or powder charge variances somehow escaped quality control as well as the associated company's testing process for each lot produced.

    Landy
     
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  19. Tim s

    Tim s

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    Well, I think it can be important but not super critical.
    I’ve had very good ammo with much bigger spreads.
    I tend to suspect, however, that it helps a rifle shoot pretty “flat” throughout the target.
     
  20. Hi-NV Shooter

    Hi-NV Shooter

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    Hi Landy, Thanks for posting you findings and testing results. I was wondering have you found any correlation between a well seasoned barrel and a overly fouled barrel as it relates to velocity.
    in other words does it have an effect if fouling affects velocity.

    Lee
     

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