.308 Bullet Weight effects past 1,000 Yds

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by M40A5 Shooter, Aug 15, 2013.

  1. M40A5 Shooter

    M40A5 Shooter New Member

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    Can someone give some insight as to why I keep getting "flak" about a .308 not able to shoot and hit a man sized target at 1,500 yards? I personally have shot at a target at 1,200 yards a few times, but there are F Class shooters out there that say this is impossible with the .308's accuracy. With this being said, I was intersted to know what grain would work for shooting this far? I usually shoot with a 175 grain Sierrs Boat Tail Match bullet (M118LR/Federal Gold Medal Match) out of my M40A5 rifle with a Nightforce 5.5-22X50mm scope, kill flash and Surefire suppresor. What would the nominal bullet drop be past that distance? Does anyone know by computation?gun)
     
  2. benchracer

    benchracer Well-Known Member

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    To do your calculations, go here: www.jbmballistics.com

    Man sized target at 1500 yards with a .308? Impossible, no. Difficult, yes.

    Even with a Nightforce, you would need to run a 20 MOA canted base to have enough elevation to get there. 40 MOA would be better. At sea level, drop would be around 95 MOA at 1500 yards. Wind drift in a 10 MPH wind would be around 18 MOA.

    Keep in mind that your bullet will enter the trans-sonic range somewhere past 700 yards. Though the Sierra 175g Matchking is known to be more resistant to upset from going trans-sonic vs a 168g Matchking, that could still degrade your accuracy. Even if you manage to put the bullet on target, it isn't getting there with much power.

    A good, stout handload with a Berger 185g Juggernaut @ 2750 would help with hit probability, but still wouldn't be packing much of a wallop.

    Step up to a .300 Winchester Magnum, launching a 215g Berger Hybrid @ 2900, and your bullet doesn't enter the trans-sonic range until past 1300 yards, is still supersonic at 1500 yards and arrives on target with nearly double the energy of a .308. Drop is only about 50 MOA and drift would only be around 9 moa.

    That would be much more sensible for reaching out that far.
     

  3. wyomingblizzard

    wyomingblizzard Well-Known Member

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    I know there are shooters out there that can hit, with consistency, at 1500 with thier 308. I also know that I can not. I have not gone past 1200 at targets other than large rocks. I ran the my load on shooter, this is what I get.
    Alt. 7000'
    Mv. 2750
    Berger 185 jugerant
    1000 yards 27.2 moa, 1645 fps, tof 1.41 sec.
    1200 yards 36.7 moa, 1458 fps, tof 1.8 sec.
    1500 yards 54.4 moa, 1199 fps, tof 2.48 sec.
    There is a lot can go wrong with a flight time of 2.48 sec. Also with my rifle I have enough dial up for 1200 but not 1500 Yards. If the wind is not to bad, I am fairly consistant at 1200. But that goes south with winds over about 10 mph. In my local it is hard to find a day under 10 mph, hard to find a day under 20 mph most times.
     
  4. Mikecr

    Mikecr Well-Known Member

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    Anyone could 'walk' shots into stupid range hits with a 22 rimfire as well. But why?
    To make youtube videos?
    There is no achievement there whatsoever..
     
  5. trigger puller

    trigger puller Well-Known Member

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    There are people that shoot out to a mile with the 308 it can be done granted there are alot of calibers that are more suited for that range but if you are just wanting to shoot that distance give it hell.:D
     
  6. M40A5 Shooter

    M40A5 Shooter New Member

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    Hello folks, you all have some excellent information. I guess I need to really try 185grain loads. The reason I am asking was for a stupid person that shoots "F" class that says that it cannot be done at all. As for shots to 1,500 yards...well out in Sabit Qadam, Afghanistan is a good target rich environment for me to practice. Just use the head dresses for wind flags and I will be just fine. As for a YouTube video, i did that already to show that you can actually shoot 5 rounds at 500 yards the size of a quarter. Of course it’s all on the shooter and a damn good rifle, but now i have some outside experience in adding extra weight to the bullet and some good ballistic calculations, along with a good website. Gents, I thank you. I will see how all of this info works, the only thing is that the M118LR is 175 grain ammo and the stuff we get is not the best by the way, it does have its inconsistencies with COA and a small variance in powder charge as well as if you were to pull the bullets, some are 172.9 to 176.1 grains and the average in a random lot was 175.4 grains. It’s not as precise as PNW Arms ammo, but it does work. After 900 yards the placement is critical. Again gents, thank you. I will get back from the field in a few weeks.
     
  7. Bart B

    Bart B Well-Known Member

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    The probability of hitting a human size target 1500 yards away with the first shot from a .308 is possible. Here's what one has to do.

    Get a zero at that target range in the atmospheric conditions its in. Otherwise, you may be off vertically several feet. Note that for every 10 fps your bullets leave from what your sight settings were established for, there'll be a 1 foot difference in drop 1500 yards down range.

    Get an accurate range to the target. For every 10 yards of range at 1500 yards, the bullet drops about 16 inches.

    Get all the cross wind speeds so wind drift windage corrections will be accurate. Note that for most heavier .308 Win. fired bullets, they drift about 2 feet for each mph of cross wind speed from 3 or 9 o'clock in the line of fire at 1500 yards down range. Wind speed varies with height; how much depends on terrain. So, with the bullet going to be about 38 feet above the line of sight at its highest point, you'll need cross wind speeds for different bullet heights above the line of sight as well as the bullets speed through them so accurate wind corrections can be made for your bullet's travel above the line of sight. You might need someone every 50 yards down range to the target with wind meters radioing you the wind speeds at each range band so your correction ensures a hit. They can put those wind meters on a long pole so different heights above the line of sight can be sampled for wind speeds.

    Get a rifle and ammo that you've shot no worse than 10" many-shot groups 1500 yards away.

    Seems to me the probability exists. Someone else can predict the probability odds or percentages of the first shot striking a knock-down blow.

    Marksmanship. . . . Anyone can shoot 5 rounds at 500 yards the size of a quarter. If they do it once, it's luck. If they do it every time, it's skill. I know of a guy who shot 10 or more egg size and smaller ten-shot groups in a row at 600 yards with his .308 Win.
     
    Last edited: Aug 19, 2013
  8. benchracer

    benchracer Well-Known Member

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    I can shoot egg sized groups @ 600 yards EVERY time. That is, if the egg in question is about 18" in diameter. What kind of egg do you think that would be?

    Just so ya know, my rifle is capable of much better than that. The nut drivin' it... not so much.:D
     
  9. M40A5 Shooter

    M40A5 Shooter New Member

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    Sorry it took so long to respond, I tried the 185 gr Juggernaut Bergers and with a little tweak here and there, I think I found a method to the madness here. Thank you much for the info and the open mind to pass the info to me. I now have a good load made up in the 185's that will be better to shoot. Again, thank you.
     
  10. Bart B

    Bart B Well-Known Member

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    If consistantly is every shot for 15 to 20 of them and fired without artificial support. . . .

    Not on a 1 MOA diameter target. And rarely with a 2 MOA diameter one.

    Nobody's consistantly hit a 1 MOA diameter target at 1000 yards with a .308, either.

    With artificial support of the rifle, one might do it at 1500 yards on a 1 MOA diameter target for a couple of shots, but rarely with the first one.
     
  11. Canadian Bushman

    Canadian Bushman Well-Known Member

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    In my honest opinion i would agree with the army and say the effective range of the 308 is 800 yds. I mean from a season to season with multiple lots of ammo standpoint. The 308 has won many 1000 yd matches and dispatched many of critters at extended ranges, but simply doesnt have the balls and bc to do it cold bore day in and day out.
     
  12. MontanaMarine

    MontanaMarine Well-Known Member

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    I've spent some time exploring the outer limits of 308 Win peformance.

    1500 yards will always be a low percentage first-round hit probability on a 1-moa size target, for a 308. I don't believe there is any getting around that. At that distance it's running out of gas even with the best LR loads. Any changes in temp, mv breeze etc is going to make a significant change in POI. I only shoot the 308 that far for the challenge and amusement.

    I shoot a moly'd 208 AMax seated to 3.08" oal, over 49.0 gr RL17, in Win brass. This gives 2620 fps from my 22" Rem varmint barrel.

    This load is surprisingly accurate and consistent to past 1500 yards, at 4500' elev. Same load shot well to 1500 meters at 2900' elevation.




    Probably the best bullet I've played with in the 308 for really going long has been the 215gr Berger. I've only played with a handful of them, but made 2600 fps with a 26" barrel and RL17. G1 BC is in the .690's, anyone can run the calcs on that and see it will be running 1200+ fps out to 1500 yards even at sea-level.

    I only pushed to 215 Berger to 1200 yards, at 4500' el, and it was very accurate at that distance, shooting at sub-moa size rocks. It's a bullet I need to play with some more one of these days.

    Here's some more info on the 215gr Berger I had posted a while back when I shot the few I had.

    http://www.longrangehunting.com/forums/f19/215gr-berger-hybrid-308win-104197/
     
  13. benchracer

    benchracer Well-Known Member

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    I have been shooting 185g Hybrid Hunters/RL-17 from my 700VS in .308. Though I have seen some folks shooting the 208 AMAX's with some success, I had never even considered that a 215 Hybrid would stabilize from my 12 twist barrel.

    I am absolutely stunned at your results! Good read. Thanks for posting the link.

    I have some 215's on backorder for my .300WM. I may have to try them out from my .308. Where I normally shoot, the altitude is around 1800ft. ASL. It will be interesting to see if they fly straight at that altitude.
     
  14. Bart B

    Bart B Well-Known Member

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    I wonder what the peak pressures are for 200+ grain bullets leaving a .308's 22 inch barrel over 2500 fps.

    Having shot several hundred 200-gr HPMK's from 26 inch barrels leaving just under 2500 fps (48 grains of IMR4350 in thin WCC cases weighing only 150 grains) and noting their pressures were high from visible signs and others measuring it with Oehler's system getting about 64,000 PSI in tight bored barrels, I can imagine what such loads might produce.