COAL or charge first?

Discussion in 'Reloading' started by Deederswy, Apr 25, 2013.

  1. Deederswy

    Deederswy Well-Known Member

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    Hey everyone, I just picked up some berger VLD's for my 7mm mag and from what ive read every where COAL is pretty important when making up your loads for the best accuracy. Ive never really played with COAL, ive usually just gone with whats in the book so this is pretty new to me. These are new loads so im starting from square one. When starting with these loads, should i work the COAL first where i start with a base charge say at 66gr(will be using H1000 powder) and start playing with the COAL, or should i seat all bullets the same and play with my powder charges first and then COAL? Thank you for any info you can give!
     
  2. MudRunner2005

    MudRunner2005 Well-Known Member

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    I did charge first, then COAL.

    I picked a designated COAL and stuck with it. Found a powder and charge that it shot the best with. Then from there tinkered with COAL to shrink the groups even more.

    What grain did you get? My 7Mag loves the Berger 168 VLD's backed by H1000.
     

  3. Deederswy

    Deederswy Well-Known Member

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    Ive read that the 7mag, 168vld's and H1000 is a great combo so thats what i went with. I took awhile to find the 168's and even the H1000 but I found some and im pretty excited to start loading and see what performance i get!
     
  4. MudRunner2005

    MudRunner2005 Well-Known Member

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    Once you get your charge figured out, and your depth set, I'm positive you will enjoy the results.
     
  5. PowellSixO

    PowellSixO Well-Known Member

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    I'm working on the exact combo you are working on right now. I went out last night and found my max load. I started at 65 gr and worked up .5 gr at a time until I hit 70 gr. At 70 gr's I didn't have bolt lift issues but my primer was flat, so I called it good. So I'm gonna call 69.5 gr's my max load, and that's exactly what Load Data said would be my max load with the H1000 and the 168 bergers. So I was pretty pleased. Not to mention I was getting 3026 fps with the 69.5 gr round. I couldn't be more pleased with that! I was seating all of my bullets to the lands when doing my testing. I'm gonna do as berger says now and load several rounds at 69.5 gr's but play with the seating depth and see what I can get for accuracy. If I can get .5 moa I'll call it good. If I can't I'll play with different powder amounts after that and more seating depths. It was very windy yesterday when I was shooting, but I could really see the rounds starting to tighten up at 100 yards when I approached my max load, and that was with different powder amounts. I'm thinking that I will be able to get some good accuracy with just playing with my seating depths. Here is a picture of my target. The first two shots were at the bottom right (just to get on paper and see if my chrony worked). The next three were at the top right. The next three were at the bottom left, and the last three were at the top left. I didn't play with the scope adjustments at all mind you.
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  6. Deederswy

    Deederswy Well-Known Member

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    was the top left your 69.5's?
     
  7. PowellSixO

    PowellSixO Well-Known Member

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    Every shot was a different weight. The top left was 70, 69.5, and 69 gr's.
     
  8. Deederswy

    Deederswy Well-Known Member

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    Oh were you just finding your max load?
     
  9. PowellSixO

    PowellSixO Well-Known Member

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    Yes. Just max load. Friday I'll be back at it. I'll load 30 rounds or so all at 69.5 gr's, but different seating depths. I'm going to do exactly as Berger recommends.
    From Bergers website:

    " The VLD (Very Low Drag) bullet design was born from a request made by the US 300 Meter Shooting Team. It was determined that they were dropping points late in the matches due to recoil fatigue. Bill Davis and Dr. Lou Palmisano were asked to design a bullet and case combination that shot flatter than the 308 case and 168 gr bullets the team was using at the time. After a design was created Walt Berger was approached to make the bullet. The 6mm 105 gr VLD was born and shot by the US 300 Meter Shooting Team using a 2” PPC (modified 220 Swift). This combination shot with less felt recoil and a flatter trajectory than the 308 case using the 168 gr bullet and higher scores were the end result. This successful bullet design soon found its way into all long range target competition and the VLD shape spread into all other calibers.

    The VLD bullet design is a combination of two very specific features. The first is a boat tail which is common on long and heavy bullets. The second and most important design feature is the long secant ogive. It is this ogive shape that allows the bullet to experience less drag as it flies to the target. This reduced drag is how the VLD shoots flatter and is less affected by wind (less drift) than other bullets. Reduced drag also translates into higher retained velocity. These are important results if you want your bullet to help improve your accuracy by requiring less sight adjustments when conditions change.

    For years we have relayed that it is best to jam the VLD into the lands for best performance. This works for many rifles however there are many rifles that do not shoot the VLD well when the bullet is jammed. We have learned that the VLD can shoot best as much as .150 jump off the rifling. VLD bullets can be sensitive to seating depth and it has been found that these bullets shoot best in a COAL “sweet spot”. This sweet spot is a COAL range that is usually .030 to .040 wide.

    The quickest way to find this sweet spot is to load ammo at four different COAL. Start with a COAL that allows the bullet to touch the rifling. The next COAL needs to be .040 off the lands. The third COAL needs to be .080 off the lands. The last COAL needs to be .120 off the lands. One of these COAL will outperform the other three by a considerable margin. It has been reported that the VLD bullets don’t group as well at 100 yards but get better as the bullet “goes to sleep” at further ranges. We have learned that by doing the four COAL test you will find a COAL where the VLD bullets will group well at 100 yards. Once the COAL that shoots best is established you can tweak +/- .005 or .010 to increase precision or you can adjust powder charges and other load variables. Frankly, those who do the four COAL test usually are happy with the results they get from this test alone. "
     
  10. MudRunner2005

    MudRunner2005 Well-Known Member

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    I'd load 1 touching, one .010", .020", .030", .040", .050", .060", .070", .080", .090", and .100" off.

    You're only shooting 11 bullets. And you will find which one shoots the best out of your gun. Shoot each bullet at different specific spots on the target to verify which one shot closest to your 0.

    For my hunting rifles I will load them up to about .003"-.005" from the length of the magazine box so I get them as close to max length as I can, but still be able to shoot as a repeater, and not a single-shot.

    I have found that 2 of my rifles prefer the heavies right up on the lands. And they are shooting 1 hole small cloverleaf 3-shot groups.
     
  11. Mikecr

    Mikecr Well-Known Member

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    You should pick a mild load, follow Berger's advice to find best OgvOAL, and then move onto ladder testing with your first powder choice.
    If nothing good comes of the ladder, change powders and run again.
     
  12. cwinner

    cwinner Well-Known Member

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    +1, it has taken me a while to figure this out but adjusting the OAL length first has worked great for me with Berger bullets.....it saves a lot of powder too!
     
  13. Thumper1991

    Thumper1991 Active Member

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    Right now doing this same thing with the same Round. Berger 168 vld h 4831sc. I first found seat depth (which is what Berger recommended to me. there is a thread somewhere here recommending this) now I am going to find my 2nd node. There seems to be alot of seat first then powder vs powder then seat. My concern was when you change seat after powder. It would change pressure. So I opted seat first. My memory (which isn't the best.) Eric from Berger agreed.
     
  14. MudRunner2005

    MudRunner2005 Well-Known Member

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    Looking back, I was playing with powders just to get the hang of reloading, so I was picking mid-range loads and going from there with my COAL.

    Of course, my STW and the 180's are up against the lands, my .308 with the 210 VLD's are crush-fit, too. Seems the Remmy 700's like them as close to the rifling as you can get. My A-Bolt is not quite as picky, and my Accumark .257 Weatherby has too much freebore for it to touch the lands, so I just press the 7Mag Browning and the .257 Wby ammo to fit about 0.005" inside the magazine length, since they are mainly my hunting rifles.

    Not every rifle will be the same, but this is what works for mine. Also, every Remington 700 I reload VLD's for, including my buddy's .300 WinMag, likes them pressed up on the lands.