How Do You Get A Low "ES" Velocity Number ??

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Down Under Hunter, Nov 15, 2007.

  1. Down Under Hunter

    Down Under Hunter Well-Known Member

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    Just thought I'd post a real no brainer for a number of you out there.

    Assuming you have a quality rifle that has been put together accurately by a smith with some real ability, and you are meticulous with your loading, what are the things you must do to get a low average spread of velocities when using a chrono ??

    I have only ever used basic stock production rifles and have noticed that I have routinely had velocity spreads 10-25 fps diffence between shots with occaisonal flyers
    .
    Will a high quality custom rifle assist in bringing the average between shots down ??

    Or is it strictly loading related issues ? Quality of chrono etc...?

    I would love to see single digit spreads or low teens without the flyers !

    Cheers
     
  2. Wild_Bill

    Wild_Bill Well-Known Member

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    Low ES

    Hi the first thing to do is listen to instructions given to you from the Gunsmith.

    But as a rule I use cases that have been prepared by removing all burrs and are a uniform length.
    When choosing components I want a powder that will almost completely fill the case and still give me the desired velocity. The more in the case the more consistant the primer ignition into the powder coloum. If their is to much air space the powder can flow up to the front off the case and the primer flash won't ignite as consistantly.

    Don't be woried to have a compressed load if using ADI powders (Hodgden Extreem). You can use a long drop tube and a full neck then seat the projectile into the powder colum. make sure you don't cause the case to deform if this happens you have to much in the case.

    The other thing is the primer as an example a 223Rem. Say you are loading with a 40 gr projectile and AR2207 (H4198) a cool primer like a federal is great but a Rem 7 1/2 is to hot and will blow shots every where now a 223Rem with a 90gr you would use AR2208 (Varget) the Fed primers will usualy blow unless in a rifle with a bushed firing pin and they will still blow but put the long burning Rem 7 1/2 is perfect we use gthem for up to 45gr off AR2213SC (H4831SC).

    "o primers will change a lot but with large cases off slow powder the best two I have found are Fed215 and also CCI BR2 primers.

    The last thing is good neck tension. This can work with a tight neck and also with the projectiles into the lands.

    As a last resort start moving the projectiles away from the lands 5 thou at a time but be aware some projectiles will never shoot verry well in some barrels and in oyhers they shoot through the same hole.

    Hope this helps

    Cheers Bill
    Australia
     

  3. Shawn Carlock

    Shawn Carlock Sponsor

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    My notes on low ES, in order.

    1. Sort bullets by baring surface.
    2. Sort bullets by forward baring surface to base.
    3. Get consistant case volume, I do this by taking once fired cases, trimmed to length, prepped and weigh them.
    4. Use a bushing sizing die with the right neck tension.
    5. Graphite powder the inside of the neck of the case.
    6. After seating the bullet set all bullets to the same length based on the OAL from the forward baring surface to the base of the case. This will give you more consistant effective case volume and jump to the lands.
    7. Experiment with load variables, powders and primer combos. Hogden Extreame powder seem to be better about this. Certain primer powder combos also seem to work better together.
    8. If you get in the low teens and or single digits be happy don't strive for a goal that makes no practical difference. At 10-15 fps ES most people will never see a difference in the performance vs. 7 or 8 fps ES.
    9. Your shooting an Edge - H1000, CCI 250, 300 SMK's and follow the above you'll be a happy guy.
     
  4. NYLES

    NYLES Well-Known Member

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    Shawn,

    How bout an article on this subject? I know you write alot but a good article on proper reloading would be awsome....some of us(me) get a lil confused on things and we are also very spread on our total knowledge on the "RELOADING" subject.

    I guess Im trying to say that there are alot of ways to do things but Im in search of the quickest, easiest, less time on the reloading bench process here and dont like shooting a 100 rounds to be satisfied. Yea, I do wish Kirby put out factory ammo for his AM's, but that aint gonna happen!

    Maybe Im askin too much, I read and read but still find myself lost sometimes!
     
  5. jmden

    jmden Well-Known Member

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    One item not mentioned so far that I've been told to do and finally did and has worked is to use heavy for caliber bullets, which if you follow Shawn's recipe for the Edge, you'll be doing. Seems to be more consistent fps #'s among other things. Have fun with that Edge!
     
  6. Shawn Carlock

    Shawn Carlock Sponsor

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    Nyles,

    I could probably do that. Reloading is one of those subjects that alot of different people think alot of different things. I could write one based on what I do though.
     
  7. NYLES

    NYLES Well-Known Member

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    I would enjoy it greatly and probably learn alot! and for the benfit of the dought on my personal knowledge, I will purchase the newest latest "RELOADING" book I can find. I noticed the dates on some of my hand me down books that I have are dated before I was born. Based on that Im sure I have some bad habits!
     
  8. blackco

    blackco Well-Known Member

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    While you guys were conversing I started a thread in the handloading forum asking for reloading techniques. NYLES had the idea, I just posted it over there.

    I would also appreciate reading an article from Shawn on the subject. If you do undertake that project, thank you.
     
  9. overbore

    overbore Well-Known Member

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    Adding to Shawn

    I have a chart of primer variables that must be factored into low ES numbers but the quick and dirty for large rifle accuracy uses is to use BR-2 primers as they are consistent and MILD . As I recall, the Win primers are also consistent but Hot, Hot! More to follow. Chart is filed under "S" as in "somewhere" but process of elimination will have me look in my reloading log--eventually--- Overbore
     
  10. Down Under Hunter

    Down Under Hunter Well-Known Member

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    Thanks Shawn and Bill for your thoughts on this.

    How do you measure the 2 bearing surface measurements ?

    I'd also love to see a " loading cook book ". Maybe you could call it " My Eleven Secret Herbs and Spices For Practical Reloading " by S Carlock !!!!

    What do you thinks about that SC ?
     
    Last edited: Nov 15, 2007
  11. goodgrouper

    goodgrouper Well-Known Member

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    I have to politely disagree on some of the above points. Es and/or standard deviation is most easily affected by powder type and the amount used. This accounts for 90% of either a bad or good deviation. All the other stuff you mentioned has some effect but all combined makes up the last 10%.

    Here's my proof:
    I mess with this stuff for a living and I can tell you that I can take un-prepped cases, un-measured bullets, dry necks, bad seating dies, and any other manner of garbage and still produce good deviations with the right powder and charge. It may not be the best and will surely improve if all the other stuff is done to the equation, but satisfactory results can be achieved. (We are of course talking about velocity uniformity strictly here and not at all about accuracy.)On the flip side of that coin, you can have perfect brass, perfect bullets, perfect dies, exactly matching case volumes and still produce horrible standard deviations.

    The key to a low standard deviation is powder, powder, powder and how much you are using of it. Primers can change things as well, but if you're going to change primers, you could have just as easily changed powders and you're still going to be back at square one.

    And the comment about Hodgdon usually giving smaller SD's: I have never seen that at all. Nothing even remotely like it. I can and have gotten sd's in the 50's with just about all the Hodgdon powders and as frequently as any other brand. If your gun likes Hodgdon, use it. If it doesn't, don't beat your head against the wall trying to MAKE it like it. Just try another powder and almost like magic the numbers can improve.


    Also, a good load that has a standard deviation of 6 or 7 fps will probably be more likely to keep those numbers throughout the aggregate than a load that has 15 fps. So try to get sd's down as low as possible. If you can't get them any better than 15, don't give up on it entirely. Just go check for group size at long range and you might just be surprised.

    An SD of 6 or 7 just shows me that there is a good node there and I'm on the right track with my powder choice.

    If you're just shooting out to 300 yards or thereabouts, you can just pick a load that has good accuracy and forget the numbers if you like but I can't do that. I want my ammo good for every situation close and far. And good numbers still show you what the map says for finding an accuracy node anyway.
     
  12. Michael Eichele

    Michael Eichele Well-Known Member

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    Ditto, ditto, ditto.

    Did I mention ditto?

    Well put GG.
     
  13. Steve Shelp

    Steve Shelp Well-Known Member

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    When I read the original post and then all the responses on pg 1, I was forming my thoughts on my own reply . But when I got to pg 2 I read goodgrouper's response. And I concur.

    Powder, primer, and load is worth the biggest chuck of the small ES numbers and accuracy. Then play with (increasing) neck tension. That has been the trend I have seen in my rifles over time.
    All the other stuff is usually worth unmeasurable differences that can only be "seen" with the use of statistical analysis. Or sometimes you do things "because it makes me feel better" and you have more confidence because of it. Which is not a problem, just don't talk yourself into believing it for real after time. And that is from a long range benchrest shooter. I'm a perfectionist and love details. One of the reason I love shooting BR competition. But the longer I play this game the less fancy stuff I do at the reloading bench and the more I try to do at the shooting bench tuning loads.

    I've seen guys try a lot of wildcats, fancy shoulder designs, worry about 1/2" tighter or looser twist, etc etc. But there are certain cartridges and powder combinations that simply work no matter what you do to them. And when a load starts shooting consistant small groups on paper at long range you can go back and shoot across the chrono and the numbers will be good. But the flip side of the coin isn't the same outcome. You can shoot across the chrono with good numbers and you might spray the target at long range. Kirby touched on this in another post last week also when dealing with some of his customers. Don't let the results of the chrono drive the bus. The old saying about "the proof is in the pudding".... for long range shooting "the proof in on paper". The group size and shape should drive the bus. Everything else is just an exercise in wearing out a good barrel and wasting good bullets.

    These may sound like strong words and it's not my intent to be confrontational at all, but if you concentrate on working on a good CONSISTANT load in variying conditions that stays accurate with only a small amount of tweaking to keep it grouping tight.... the ES numbers will be there without using many "tricks".


    just my experience,

    Steve
     
  14. Shawn Carlock

    Shawn Carlock Sponsor

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    I guess I should have clarified by post a little more. I too agree that powder charge/primer selection are the biggest keys to low ES, by far. Once you have gotten as far as your going to go with that to get the lowest possible you work the neck tension and case volume. Graphiting the neck directly effects consistant neck tension. Everyting else is geared around consistant volume and jump to the rifling. When I first realized the huge effect of ES at extreme distances and started to look at how to lower it in one of my first Edge's the first thing I did was switch from FED Mag. Match primers to CCI 250's and cut my ES almost in half and was in the mid to low teens. Graphite, consistant bullets, consistant seating depth based on forward baring surface, and case weight got me into mid and low single digits. Loaded like this out of 10 rounds I get 6 or 7 exaclty the same. I shot some test groups @ 1276 yards with a 5-8 ES group and a 12-14 ES group and got a average group difference of 1.7 inches. A 25 ES group was scary in comparison. GG is absolutly correct in saying that powder / primer combos are by far the most important, it just depends on how much performance your after as to how much work you want to put into it. I am the king of I like to shoot not reload so I don't invest my time in reloading activities that have not proven to be a benefit. Hope this helps. In the end alot of people have different experiences and opinions and this is mine.