Velocity vs Accuracy?

Discussion in 'Reloading' started by Rickyrebar, Apr 4, 2010.

  1. Rickyrebar

    Rickyrebar Active Member

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    Worked up my 1st hand-loads last weekend, was quite a rush to finally shoot my own stuff!
    Using Nosler #6 manual recommendation for a starting point and max load, I loaded 3 rounds of each in 1/2 grain increments (60 Gr. - 64 Gr.).
    I found that the 60.5 Gr load to be scary accurate, basically put 3 shots into a pattern where they were all touching one another. As I continued to shoot the heavier loaded rounds accuracy diminished (still much better than any factory loads I have ever shot). I went clear up to the 64 Gr load with no signs of pressure.
    Anyhow, so here I am and where do I go from here.
    The most accurate rounds I loaded were the lightest loads.
    Per the Nosler #6, it tells me the MV of the most accurate load I shot is around 2826 f.p.s.
    I love the accuracy, but, being a guy my, natural instinct is that, bigger is better, more is better. I do not have access to a chronograph, so I have no idea what the actual MV is in these loads.
     
  2. ss7mm

    ss7mm Writers Guild

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    Don't have any idea what your shooting, cartrdige bullet etc. without guessing, but I can tell you this. It wouldn't do you any good if you could run them up to 4,000 fps if the accuracy was only "minute of mountainside".

    I always look for the most accurate load, not the fastest. If they end up being one and the same then great but accuracy is what lets you hit stuff. Knowing the range is easy and dialing for the given load and field conditions is easy. Hitting something with a load that only shoots "MOM" won't make you very happy.

    I'll take bugholes over a shotgun pattern every time.:)
     

  3. 4bycamper

    4bycamper Well-Known Member

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    [QUOTE
    I'll take bugholes over a shotgun pattern every time.:)[/QUOTE]

    +1
    Finding an all-weather load that shoots tight groups ... priceless.
     
  4. Rickyrebar

    Rickyrebar Active Member

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    300WSM Nosler BST 180 / W760 Powder
     
  5. Buffalobob

    Buffalobob Writers Guild

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    Sounds like you have either a bedding problem or your action is not square and is torquing as the pressure on the bolt increases.

    As far as accuracy goes you need enough to hit what you shoot at. You have to decide what you are going to hunt and how far you are willing to shoot then you can determine the MOA of the kill zone and then back into the accuracy needed. You should add some safety margin.
     
  6. Fitch

    Fitch Well-Known Member

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    Your rifle is acting just like the Nosler manual says it will. The most accurate load for that bullet with that powder is the lightest load. It doesn't always work out like that, but it did this time. The good news is you know at least one load that shoots tiny groups. You "really" need to know how fast it's going.

    None of the powders listed for that set of bullets are most accurate at max load.

    What to do next:

    1) You might try Viht N550, the manual says that powder was the most accurate with a max charge (but still start low and work up).

    2) You might ask here for loads folks use with that bullet.

    Basically what you do next is try a different powder.

    Beyond that, the very next addition to your reloading equipment list should be a chronograph. I have a CED. Like it a lot. With out knowing the velocity you are not going to be able to do any sort of ballistic projections or even reasonable calculations of point blank range based on data. Fantasizing about velocity and then doing ballistic calculations is complete a waste of time.

    Fitch
     
  7. Rickyrebar

    Rickyrebar Active Member

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    Any idea where I can find some Viht N550? Everywhere I look shows it has been discontinued.
     
  8. BENNYBOOBOO

    BENNYBOOBOO Well-Known Member

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    Sounds like you have an idea of how this works, but check out Dan Newberry's page on Optimal Charge Weight (OCW) testing. It is a sound method of doing business and has never lead me astray.

    Something else I didn't see you mention is your cleaning-cycle; are you doing all of your load testing within your cleaning-cycle both after the barrel is fouled in and before the copper takes a toll on your accuracy and gives you false POI's?

    With that said, I like to think I have a firm grasp of how this works and am usually down at the Tacoma Sportsmen's Club (not too far from ya) on weekend mornings if you have any questions while you're sending them down range. Actually, I enjoy helping people working up loads so long as they have open minds.

    EH
     
  9. Bravo 4

    Bravo 4 Well-Known Member

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    I will usually start by finding the OAL and max load for such in the rifle. Then I will drop the load charge (depending on the cartridge and time of year) to where it doesn't show any signs of pressure and then adjust the bullet seating depth till I find an OAL that gives acceptable accuracy (watch for pressure signs the whole time). If that doesn't work I will switch primers or another powder along the same burn rate until I find a max load with acceptable accuracy. Anytime you change a component you should start low on the powder charge.