Velocity deviation question

Discussion in 'Extreme Long Range Hunting & Shooting (ELR)' started by Chad Schmidt, Nov 8, 2018.

  1. Chad Schmidt

    Chad Schmidt Member

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    What is the highest velocity deviation acceptable for ELRH? I know at less than point blank range it has little effect but at long range it becomes critically important.
    Chad
     
  2. Remmy700

    Remmy700 Well-Known Member LRH Team Member

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    Welcome to the forum brother and great question. You are going to get a few different views on this question. Me personally I don't care if its a hunting rifle or a match ELR rifle I treat them both as one with exception of coarse to style of bullet I am using. If I get a 1/4 moa group with 10 SD and a 1/2 moa group with a 2 SD I am taking that 1/2 moa load all day. Most of the time with few exceptions that load will hold that 1/2 moa to distance where that 10 SD will start to open up. Sometimes the stars line up and you get a 1/4 moa group with low SD also which sometimes does happen also. I try to set my minimum to SD of 6 or less mainly focusing to attain 4 or less but again depends on the groups the gun is laying down. Not sure what your skill level is but most of the time average shooters will never even notice the difference of a 20 SD load vs a 2 SD load just because of inexperience and flaws in shooting mechanics. I have personally did load work just to see what a 20 SD load vs 5 SD load does at 1K different. You can definitely see that vertical stringing due to changes in velocity whereas with the low SD the only stringing I noticed was horizontal due to slight wind changes without compensation. I will say to attain those low consistent SD your reloading game has to be on point and attention to detail of all the little things in brass consistency, charge weights etc. has to be really cared for. Will be interested to see what some of the others say. Again welcome to the forum! Dan
     
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  3. Chad Schmidt

    Chad Schmidt Member

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    Thanks for the feedback and welcome.
    Chad
     
  4. jasent

    jasent Well-Known Member

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    F166D782-17B7-48E8-8BCB-F533708F1BED.jpeg 49E31EE2-AC0F-418C-A277-3CF720617762.jpeg I like an extreme spred of less than 20 with single digits as a goal.
     
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  5. Barrelnut

    Barrelnut Well-Known Member

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    If I can get the ES and SD into single digits, I think things are great. Last workup I did was ES=9, SD=4, across 5 shots. It has been shooting well out to 700 yards and most everywhere in between pretty good. Have it dialed in with the Applied Ballistics app pretty well. Like was said above, keeping it there across several loadings of the brass is the goal.
     
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  6. dok7mm

    dok7mm Well-Known Member

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    If you are lucky enough to find a good, fairly wide node, then you can have a very accurate load with somewhat higher ES. The target will tell you if it's working at long distance.

    I have a couple of loads that are like this, but they required very fine tuning of seating depth and close monitoring of lands erosion, to maintain 1/2 moa accuracy. Both would occasionally show extremely low ES on 3 or 5 shot groups, but the average of several 10 shot groups was always close to 20+ ES. The trade-off was that I got to use the hunting bullet that I wanted and the powder I had lots of.
     
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  7. Chad Schmidt

    Chad Schmidt Member

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    So you full length size with a bushing die or just neck size with a shoulder bump? Jasent: What cases are in the photos, I'd guess 300 rum.
     
  8. Remmy700

    Remmy700 Well-Known Member LRH Team Member

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    Dok7mm u are very correct. Below is a group with an ES of 32 during brass fire forming. I ran with that load to fireform the rest and shot out to 1k and accuracy held. Boggles my mind. I ain’t head cashier at Walmart or nothing but I would think with that much variation **** would be stringing like crazy!
    F5809E59-AEFC-4E3D-9A0C-61DE2FB72D58.jpeg
     
  9. J E Custom

    J E Custom Well-Known Member

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    Like others I prefer to get single digit SDs but will settle for Ten to fifteen on small bore cartridges.

    J E CUSTOM
     
  10. jasent

    jasent Well-Known Member

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    6D3DE93E-7DE0-4DD2-BD1D-9D4A54156425.jpeg
    338/375 ruger. Love it!!!
    That load is 250gr Berger and h4350
     
  11. dok7mm

    dok7mm Well-Known Member

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    That's pretty amazing, and that it held out to 1 K, is even more amazing. I also lucked into my 180 gr./7 STW load. Was fire forming new brass @ 400 yds and was just holding with the reticle, never dialed it, just fooling around. Luckily, I was using my LabRadar. I bumped load .3 gr and adjusted my seating depth and presto, I had my load. Wish they were all like that. IMG_20160820_131955552_HDR.jpg
     
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  12. sable tireur

    sable tireur Well-Known Member

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    This is exactly why you cannot depend on just one variable to control accuracy. There's more to it than just getting a low ES. ;):D
     
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