.308 ballistic table
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Thread: .308 ballistic table

  1. #1
    Join Date
    Oct 2007
    Tampa Bay Area

    .308 ballistic table

    So I just got me Savage 10FP in .308 and going to try my hand at some longer distance shooting. I know several of you guys have some experience in this area so wanted to ask a couple questions about the .308 ballistic table.

    1. At what distance do you guys zero your scopes?

    2. I'll probably be loading 168gr and/or 175gr Sierra match king bullets. I know the ballistics will change with the velocity that I push the bullet but do any of you have bullet drops out to 1000 yrds?

    3. Any other words of wisdom for a new distance shooter?

    Last edited by lukem; 05-01-2012 at 04:10 PM.
    "When Government fears the people, it's liberty. When people fear the Government, it's tyranny."
    - Benjamin Franklin

  3. #2
    Join Date
    Jan 2008
    Florida Panhandle

    Find ballistix for windows

    It is a shareware program and works amazingly well! It used to be on Sniper Country

  4. #3
    Join Date
    Sep 2007
    Gray Court, SC
    At that distance make sure you weigh each case and try to group the empty brass by weight. Weigh each bullet and group them also. Also weigh each charge to make sure they are identical. Any deviation form this will cause erratic grouping at that distance. If you really get into 1000 yd shooting you should also check the empty case volumes.
    USAF Retired, CATM, SC CWP, NH NR CWP, NRA Benefactor
    To preserve liberty, it is essential that the whole body of people always possess arms, and be taught alike, especially when young, how to use them... -- Richard Henry Lee, 1787

  5. #4
    Join Date
    Jan 2008
    Florida Panhandle

    Exclamation get a copy of FM23-10

    This is the Army sniper field manual. It has a lot of good beginning info!!!

  6. #5
    Join Date
    Oct 2007
    Tampa Bay Area
    Thanks guys!
    "When Government fears the people, it's liberty. When people fear the Government, it's tyranny."
    - Benjamin Franklin

  7. #6
    1. I zero mine at 200 yards.
    2. I use the 168gr Match King bullets. Here's a ballistics table from Shooting Times:

    .308 Winchester (7.62 NATO)

    3. Not sure, read some books on the subject, hang out with someone who's experienced at it, go to an Appleseed shoot to work on the basics of shooting.
    "When the outflow exceeds the inflow, the upkeep becomes the downfall"

  8. #7
    Depends on what you are sooting... What ranges and what targets.

    If you are shooting short range (under 300 yards) most of the time, and LARGER GAME HUNTING, then consider a 'Point Blank Zero' approach.

    At 200 yards, you zero in on a deer target that shows vitals.
    At 200 yards, your point of aim should be point of impact.
    At 300 yards, you will be about 1.5 Inches low.
    At 100 Yards, you will be about 3/4" high.
    This will let you blow the heart out of a deer at anywhere between 100 and 300 yards without adjusting for distance.

    Hunters should consider a FIXED power optic, since when hunting you often don't get an opportunity to mess with a dozen adjustments.
    4x or 6x FIXED optics have much less that can go wrong with them to ruin what might be an expensive hunting trip, so I usually stick with fixed power optics when larger game hunting.

    Most fixed power optics don't have 'Clicks',
    They use friction adjustments, and that will let you fine tune your rifle to be EXACTLY on at your chosen sight in range instead of 1/4" this way or 1/8" that way between 'Clicks'...

    When hunting, you don't need the tall, or exposed turrets/adjuster knobs that will get banged around by case travel, brush busting, ect.
    Once zeroed and confirmed, you simply screw on the protective caps and go hunting!

    If you are ground hog sniping, then consider a 'Target' optic with covers for TALLER target type turret adjustments.

    You WILL have to fine tune for prairie dogs or ground hogs or other really small game/varmints since they NEVER stand by your range stakes!

    Fine tuning for PRACTICED shots the range finder will throw up at you is pretty important, so the larger knobs, and adjustable knobs so you can return to zero easily will make the job of eliminating the ankle biters much easier.

    With prairie dog hunting, you usually use a rest, have a hole or holes you can range on,
    And you normally have LOTS of time to range the target area,
    And if you are practiced, you will know what to dial in for range changes from zero and windage.

    Try practice at different ranges in 10 yard increments, starting with about 50 yards and going out to about 250 yards or 300 yards so you KNOW what the bullet is going to do at any given range.
    Range it out, dial it in off your dope card, and start thinning out those ankle biters!


    For stuff like long range competition, you will need to consider a 'Canted' mount to add MOA of elevation to your barrel/optic.
    20 Degree mount for out to about 600 yards, and 30 or more for ranges of 800 or more.

    If you don't use a canted mount, you will run out of optics adjustment before you reach out that far.
    600 yard competitions with a 1" tube you will need about 20 MOA of cant in the mount so you still have vertical adjustment out that far.

    You will also need VERY PRECISE adjustments on the optics you just can't get with 'Cheap' optics,
    So figure on spending around $1,000 or more on a 'Long Range' optic that will be accurate at those ranges.
    If the optic can't repeat a '4 Square', then your adjustments are meaningless since the deviation will increase with range.


    Large caliber, heavy recoil rifles will beat the optics mounts around pretty good when the rifle recoils.

    Steel mount/rings will expand/contract at the same rate as the receiver when exposed to temprature changes.
    Aluminum expands/contracts at roughly twice the rate of steel, and roughly three times as much movement as steel.
    I've been screwed by aluminum mounts WAY TOO OFTEN to use them on anything past about 300 yards.

    Short range rifles can get away with aluminum, but NEVER try them on heavy recoil or long range rifles!

    Heavy steel mounts reinforce and strengthen the receiver, helping to minimize the twist the receiver sees when fired.

    Rings should ALWAYS have at least two screws on each side!
    This spreads the clamping force out and a single screw failure won't effect your shot.

    Optics are exactly what you pay for.
    While in Europe in the '70s on the military rifle team,
    The Europeans often commented you could tell a 'Yank' by the $1,000 Rifle and $100 Optic,
    While the Europeans had $100 rifles and $1,000 optics...
    And that is pretty accurate as far as I can tell!

    Buy as much optic as you can afford, and keep it when you trade rifles!
    A really good optic is a joy to shoot and a life long companion!
    Cheap optics will do NOTHING but give you fits, missed shots, and wasted time!

    Heavy recoil guns will beat the guts loose in lesser made optics!

    Make SURE your optic is designed for the caliber/recoil of the firearm you are shooting!
    I don't know how many optics I've owned that started out working VERY well, but soon went to crap with repeated recoil damage!

    I now buy LIFETIME warranty optics only...
    Leupold comes to mind, they have some 'less expensive' optics, but they don't make anything 'Cheap'...
    Leupold has EXCELLENT customer service, a very fine product, and they have been around forever, so it's unlikely they are going anywhere any time soon.

    Burris makes a pretty good optic, seems to live well on some of my heavy recoil rifles,
    But best if you stay out of the 'Belted Magnum' calibers with them.
    Burris does NOT have the fine tune repeatability that Leupold does, so I don't use them on competition rifles, but they work fine on hunting rifles and shorter range rifles.


    Shooting '4 Square'...

    Once the rifle is zeroed for 100 yards,

    Take a target at 100 yards.
    Draw a square, 2" square with a 'Dot' at each corner.

    Fire at the upper left corner,

    Then adjust your optics for TWO inches RIGHT,
    and aim at the Upper LEFT corner again, and fire.
    The bullet should impact the dot on the upper RIGHT corner.

    Then adjust DOWN two inches, aim at the same upper LEFT corner.
    The bullet should impact the lower RIGHT corner.

    Then adjust two inches LEFT and fire while aiming at the same upper left corner,
    The bullet should impact the dot in the lower LEFT corner.

    Then adjust two inches UP and fire at the same upper left again,
    You should have TWO holes in the upper left when done,
    And a hole in each dot in the corners.

    This will tell you if the optic adjustments are working/calibrated correctly for the 100 yard (1 MOA) range all optics are supposed to be calibrated for.

    If it comes right back to the orignal impact point, then the optic is 'True' and working as designed.
    If it doesn't, and you will find turrets that work BACKWARDS to what is marked, turrets that over shoot or under shoot their intended adjustments, ect.
    But if it comes right back to the upper left, then the optic is doing exactly what it's supposed to do.

    Some optics are 1/2 MOA per 'Click',
    Some are 1/3 MOA per Click, which makes it REALLY difficult to figure what to dial in at strange ranges!
    Some are 1/4 MOA per click,
    Some are 1/8" MOA per click,
    (MOA=Minute Of Angle, 1.047" at 100 Yards)

    So make sure you know how many 'Clicks' or marks on the dial 1" is before you adjust your optics for a '4 Square' shoot!

    Just because you have an optic that doesn't come right back to 'Zero' after adjustment doesn't mean it's 'Useless'...
    Cheaper optics usually won't come back to orignal zero, or hit the 4 Square like they should,
    But once zeroed, they are FINE for straight line shooting where you don't adjust the elevation or windage.
    Short range 'Squirrel Killers' come to mind for a suitable application.

    I usually shoot a 4 Square right after I get a new optic mounted just to see if it will do what it's supposed to do...
    If not, I return it...

    I also usually check it in on a known shooter so I know if it's the optic or rifle.
    If you use a rifle you KNOW is accurate, then it's got to be the optic...
    If you plant a new optic on a new rifle, then you have no way to tell if it's the optic or the rifle that is acting up...

  9. #8
    As for bullet weights,
    Shorter ranges (under 500 yards) the 168 Gr Serria MK is a good bullet.
    Just remember to weigh each bullet, some are off by as much as half a grain or a grain from the 168 they are supposed to be.

    Any smooth transition boat tail bullet will be better than anything 'Square Backed' since the vortex behind the bullet is lessened as it flies through the air because of the tapered tail,
    So stick with boat tails...

    If you are shooting farther than 600 yards, 600 to 800 yards, then consider Molly coated bullets.
    They will add another 50 to 200 Feet Per Second muzzle velocity by reducing friction, making the rounds more accurate.

    If you are going farther than 600 yards, remember to use heavier bullets.
    178 Grain Molly coated bullets will stay above the transonic threshold farther out, past 1,000 yards most times.
    The bullet gets REAL wobbly when it approaches transonic speeds, and if it drops below that, it's a crap shoot where it's going to impact.

    Molly coated will make your barrel last longer, and not take as many 'Fouling' shots before the barrel settles in.

    Generally, use the LIGHTEST bullet you can still be accurate with at your particular chosen range limit since lighter bullets have higher muzzle velocity and higher velocity means more accuracy (bucks wind better, less drop to target)...

    When shooting long distance, it's like bench shooting,
    Your barrel will probably take between 6 and 15 shots to foul the barrel before your groups tighten up and the barrel settles down and you start shooting well.
    My rifles have very clean, polished bores, so they usually need 6 or 8 shots to 'Come In', but I have one stubborn bench rifle in .300 Weatherby Mag that takes 15 to 18 every single time to 'Come In'...
    Very accurate when it does, but it's a PAIN to get the bore fouled correctly for it to work at long range!

    New barrels will take between 500 & 1,000 shots before they 'Come In' and really start giving you tight groups, and barrel break in is CRITICAL!

    It will take you more than 1,000 rounds to figure out things like bullet drop and 'Spin Drift' (hate that term) will place the round, so it's no big deal you are staring with a new barrel...

    'Spin Drift' is when the rifling of the barrel imparts a spin of about 200,000 RPM spin on the bullet...

    If you watch a football when it's passed a long way, you will quickly notice the ball nose will rise and slightly angle in the direction of rotation.
    Bullets do the same thing.
    If you have a right hand twist barrel (and most of us do) the bullet will to slightly nose up and to the right in flight.

    This means the bullet will deviate to the right the farther you try and reach out with it.
    When you shoot long distances, you will have to factor this 'Spin Drift' into your adjustments.
    Practice will tell you how much your particular rifle will drift right with range and the ammo/muzzle velocity of your ammo...

    The military ballistics tables might shed some light on this for you,
    But since the military shoots 5R barrels (instead of 6 groove, 1/12 twist rates most civilian rifles have) and a VERY specific ammo,
    The formula they use to determine spin drift probably won't help you as much as experience at a range will.

    So when you start 'REACHING' and the bullet strays off to the right, you know what's happening and how to compensate for it...

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