Sniper's choice : ammunition ?

Discussion in 'General Firearms Discussion' started by SWAGA, Dec 8, 2014.

  1. SWAGA

    SWAGA No longer broke... Lifetime Supporter

    Considering the sniper semi-auto vs bolt thread;
    No matter how accurate the tool it's the operator that determines precision.
    Now with that opinion out of the way I'm curious about ammo selection.

    I'm vaguely familiar with twist rates vs bullet weights and barrel lengths on accuracy.
    I know military sniper teams have their armory hand roll ammo tailored to a specific rifle.
    Now, us as lesser gods not having that luxury, how do you select your ammo for the highest accuracy?

    What gives an average to good shooter the best chance at repeatable accuracy?
    How do you select the top shelf ammo?
    There has got to be a more scientific approach then "see what your gun likes" which is probably acceptable for a pistol caliber carbine.

    Given a certain twist and barrel length how do I select ammo?
    In your experience what is the most accurate ammo in:

    5.56/.223
    .308
    7.62x39
    7.62x54r
    30.06?

    As those seem to be the most prevalent on this forum.
     
    Last edited: Dec 8, 2014
  2. ajole

    ajole Supporting Member

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    No, it really, TRULY is, see what your gun likes.

    It's the same for precision reloads..your best pet load in your gun may be crap in mine, even though we have the exact same rifle..

    There are just so many variables.

    Also...top shelf isn't always the answer. Sometimes bargain basement is right for a gun.

    The trick is, bargain basement isn't always consistently loaded, and consistency is the number one concern in real world accuracy.

    So maybe the cheap stuff works for a 10 shot string. But then the next 10 are all over the place. Or it's good for one whole box. But the next box may be a different lot number, and shoots like crap.
    Top shelf stuff will be more consistent over boxes, the question is, how accurate is it in your gun?

    This is why reloading is the answer. It doesn't matter what the factory makes, or how the lots are. You control it all, at a very fine level. Some guys reject half the boolits in a box of 100, as they are .5 grains off the rest.;)
     
    Last edited: Dec 8, 2014

  3. SWAGA

    SWAGA No longer broke... Lifetime Supporter

    If I give you a twist rate and barrel length what's the starting point?
    Boat tail spitzer bullets?
    How does ballistic coefficient tie into accuracy?
    Would you go for the bullet with the lowest ballistic coefficient?

    I understand manufacturing tolerances ( both ammo and gun) will determine what ammo your gun 'likes' but there has to be a starting point where you can narrow it down and only have to test shoot maybe a half dozen bullet/charge combo's instead of hundreds.
     
  4. FlashBang

    FlashBang I Stand With Talon Lifetime Supporter

    Unless you are hand rolling your own for each specific firearm, the best advice I can give you is to try different ammo until you find the one that works best for you. Even then, as AJ said, you may find it changes from run to run.

    While many people love it, I find Hornady Match ammo to give crap performance in the firearms I have tried it in, while PPU gives great performance.

    There are a LOT of variables in coming up with the best round for your firearm.

    I have a couple of .308 Savages, same model, and each one has its own load that it does its best with.
     
  5. Johnny_B_Goode

    Johnny_B_Goode Member

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    Target shooters like boat tail hollow points. The hollow points are not designed to expand. Target hollow points are to create a ballistic bubble so the bullet has less drag and less push from the prevailing winds. Target barrels are rifled for bullets that win certain events.
     
  6. planosteve

    planosteve Lifetime Supporter

    I have been using the Herters and Monarch in my 06. They are made by PPU and both shoot an inch or less at 100 yds consistently. They even have PPU head stamps.
     
  7. ajole

    ajole Supporting Member

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    Depends on the caliber.

    Generally, it's heavier bullets need more twist, and standard twist rates are based on the standard weight for caliber, as in the .308 being a 150 grain from the original design, or the .223/5.56 being a 55 grain, though as times change, so does the "base" idea, ie, many see the .223/5.56 as a 65 grain norm. But many target/varmint rifles in .223 still have a 1 in 12 twist, as they shoot 55 grain and lighter bullets.

    So...go with what was the original specs.

    Then it depends on the type of shooting. At 100 yards, you want either slow bullets that never break the sound barrier, or fast bullets that never decrease below the sound barrier prior to hitting the target. Usually, this only comes up with .22LR.

    At longer distances, fast is generally better, as the holdover for subsonics tend to get ridiculous, and more time in transit gives more wind drift, spin drift, and other issues.


    This also depends on the type of shooting. Short range shooters seem to prefer the flat base, as it's a more consistently concentric bullet.

    At long range, the better BC and weight forward configuration of the boat tails (relative to the flat points) gives them an advantage.



    Basically, as a bullet flies farther, any drag decreases speed, and as the bullet loses speed, it becomes less stable, especially as it drops into subsonic flight. Also, the center of balance is a big deal, weight forward is more stable, weight to the rear less stable.

    Flat points of the same weight as a boat tail are weighted to the rear a bit more. At long range, that's a bad thing.

    Spizters are weighted slightly more to the rear than a round nose, but they are ballistically superior, so the trade off is acceptable.

    And heavier bullets tend to lose speed slower, and are longer, giving a better BC, so they stay accurate longer.


    NO. Higher BC is better.;)

    Here's some good info:

    "The 6 mm and 6.5 mm cartridges are probably the most well known for having high BCs and are often used in long range target matches of 300 m (328 yd) – 1,000 m (1,094 yd). The 6 and 6.5 have relatively light recoil compared to high BC bullets of greater caliber and tend to be shot by the winner in matches where accuracy is key. Examples include the 6mm PPC, 6mm Norma BR, 6x47mm SM, 6.5×55mm Swedish Mauser, 6.5x47mm Lapua, 6.5 Creedmoor, 6.5 Grendel, .260 Remington, and the 6.5-284. The 6.5 mm is also a popular hunting caliber in Europe.

    In the United States, hunting cartridges such as the .25-06 Remington (a 6.35 mm caliber), the .270 Winchester (a 6.8 mm caliber), and the .284 Winchester (a 7 mm caliber) are used when high BCs and moderate recoil are desired.

    The .30-06 Springfield and .308 Winchester cartridges also offer several high-BC loads, although the bullet weights are on the heavy side.
     
    Last edited: Dec 8, 2014
  8. mrgreen

    mrgreen Member

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    1-7 twist rate .243 with 107 grain i am building another now and i have a suppressed one now that with 100 grain Barnes will shoot quarters at 300 yards

    I happen to like the .204 ruger caliber if i was going to shoot 300 and only need to do head shots, woodchucks, or paper.

    the .270 is a nice round too

    25-06 is good as well as the 6.5

    alot just use the .308 but i prefer the .243 and the main reason i want to reload myself. Her is the one rifle i have i don't have the other one done yet and i am now working on chambering a new project that will be really cool and suppressed too
     

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  9. USMC_VET

    USMC_VET Supporting Member

    For my Savage Axis .308 I found my groupings get sub moa at 100 yrds especially if I use good quality ammo that is boat tail design and using 150 grain . If I use the same ammo I'm still showing tight groupings past 300 yrds

    Now let's say I use Winchester super x 180 grain the groupings suck bad as it opens up to 5-6 inch @ 100 yrds
     
  10. planosteve

    planosteve Lifetime Supporter

    My Ruger American 06 has about the same as it likes the 150's also. The 168 BTSP are about as good but it does not like any of the 180's as the groups open up to 2 inches plus at 100 yds.
     
  11. mrgreen

    mrgreen Member

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    Hornady 150 grain in that American 30-06;)
     
  12. Bull

    Bull Just a Man Supporting Member


    Buddy of mine hand rolled for his 25-06 Ruger, can't recall which model, but it was nice.... That thing was a frickin one hole laser beam machine!
     
  13. USMC_VET

    USMC_VET Supporting Member

    I'm using American Eagle 150 grain BTand is the best ammo I've found so far that has worked well in my Savage Axis .308
     
  14. Bull

    Bull Just a Man Supporting Member


    Thanks Vet, I'm gonna have to try some.
     
  15. Branth

    Branth Member

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    Twist rate and bullet weight are a good place to start. You need to be sure that your barrel is gonna adequately stabilize the ammo you're shooting. If you have a bolt .223 with a 1-14" or 1-12" twist rate, you can't shoot 65gr bullets through it and expect any degree of accuracy. Overstabilizing is better than understabilizing, but that can actually decrease accuracy as well, as in a 1-7" twist .223 with really light bullets. The best accuracy is often found on the edge of stability - I have a 1-9" twist that likes 65gr bullets a lot, which is just on the edge of what it can stabilize.

    One thing to note is that technically speaking, bullet weight is irrelevant to stability - What matters is bullet length. With bullets made of copper jacketed lead, they're basically the same, but pure copper bullets are longer than equal weight normal bullets, some very aerodynamic bullets are longer, and weird stuff like tracers are longer as well. Those would stabilize like much heavier bullets.

    I also look through my loadbooks and see what powders give good velocity without really high pressures.

    Beyond that, it really is experimentation. Are you talking about off-the-shelf stuff, or rolling your own?
     
  16. moona11

    moona11 King of you Monkeys Lifetime Supporter

    I like the ammo that hits what I'm aiming at. :-D
     
  17. SWAGA

    SWAGA No longer broke... Lifetime Supporter

    I'm talking of the shelf stuff not unobtanium.......
    As my barrel is x, my twist rate is y so I'm starting with --- and working my way up to ---
     
  18. Branth

    Branth Member

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  19. ajole

    ajole Supporting Member

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    Really...in .30 cal, there's a ton of 1 in 10 twist barrels, that shoot everything from 150-200 grains just fine, which is where 90% of the .30 cal bullets are found.

    If you go smaller like 6.5 to 7 mm, you might go to 1-8.

    And Branth already talked about the .223 stuff.

    Another funny thing, is the fact that at sea level, you need more twist than I would up here at 5000 feet.
     
  20. USMC_VET

    USMC_VET Supporting Member

    Also if you shoot more than one grain of ammo like 150,168and 180 you will need to re zero ea time you change your bullets . Also like what I did and is very helpful is creating a DOPE log book . This log book is very helpful for a sniper