optimal bullet weight

Discussion in 'Ammunition & Reloading' started by matt g, Oct 23, 2007.

  1. matt g

    matt g New Member Supporter

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    What would the optimal bullet weight be for a gas operated rifle with an 18 inch, 6 groove, 1:11 twist barrel chambered in .308 Win? Should I be running a heavier bullet with the higher twist rate?
     
  2. Bidah

    Bidah New Member

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    You will probably find that twist will prefer the 155 to 180 grain bullets, with a preference for 165 to 173 grain bullets. It could take years of experimenting to find the right combination.. :) That is if you are looking for perfection.

    -Bidah
     

  3. Catfish

    Catfish New Member

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    I would think that Bidah about hit it. You can go to Berger Bullets web page and see what of their bullets they recomand for an 11 twist barrel. I pretty sure it won`t be above 180`s.
     
  4. Bidah

    Bidah New Member

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    I am not sure why you are looking at heavier bullets, but for .308, you can find that most of the good ones are 155 to 178 grains. I personally don't see the need for the 180's or heavier as they are more of a specialty bullet. If you want to shoot above 180's, you need a 1/10 twist or better.

    So, what are you looking to do with it?

    -Bidah
     
  5. matt g

    matt g New Member Supporter

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    I'm just wondering what bullet weight I should be using in my M1A. I found a good source for Winchester loaded NATO specd 147 gr. 7.62x51.
     
  6. Bidah

    Bidah New Member

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    Well for accuracy, those are not the best as they vary in weight and uniformity a bit. They are great for general shooting though, and I use a bunch of them. What I said before still stands, and that is certainly the case for M1A's.

    -Bidah
     
  7. rickrem700

    rickrem700 New Member

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    M1A 1 in 11 twist

    I shoot Federal 168 grain hpbt out of mine, It was the first flavor I ever ran through the gun, and she print's 1/2 inch 3 shot groups all day long at 100 yards, So I stuck with that round, Mine is the same rate of twist as yours so you should be right in that ball park, If I were shooting past 400 yards I might step up to a 174 grain just to give it that little extra a$$ it needs to stay accurate, Don't quote me on this but the last time I checked out the bullet speed on this gun with this ammo, it was reading 2,685 feet per second about 10 inches from muzzle, Anywho this is what works for me and mine, Good luck.
     
    Last edited: Oct 25, 2007
  8. matt g

    matt g New Member Supporter

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    Is yours a Springfield Scout/Squad, full size or SOCOM?

    I don't think it matters too much what you're shooting when shooting under 300 yards. At that range, it is more shooter than ammo. I'm wondering what to use out past the 300 yard mark, which is why I was asking about the heavier bullets. I'm sure that the M1As are good out to 800+ yards. I'd just like to be able to practice up and be able to make shots like that.
     
  9. Bidah

    Bidah New Member

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    The 168's will shoot that far, but you would probably do better if you can find some 173 or 178 grain bullets. Hornady makes the A-Max at I believe 178, Nosler makes a BT at 175 or 180, and Sierra makes one at 180 I believe. For those long shots these weights would do better. Get one with the highest BC that you can that will work well in your rifle.

    A number of years ago I got a bunch of 173gr FMJBT that was from military match ammo that was also used as a sniper round. I do not have many left, but they are very good bullets.

    -Bidah
     
  10. matt g

    matt g New Member Supporter

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    How will the ballistics be with the 180 gr. in a 1:11 barrel? Wouldn't the 180 gr. be better suited for a slower twist?
     
  11. rickrem700

    rickrem700 New Member

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    M1a

    Mine is a full size, A 168 grain is as small as I would go personaly and will take you to six hundred yards easely no problem the 1 in 11 twist will handle 180 out to a 1000 yards with ease, when I said I would take it to 174 grain out past 400 yards that was just personal preferance your gun will handle 168 grain up to 180 as those are the recamended bullet weights for that rate of twist, mine prints 4-5 inches at 600 yards I am sure I could tighten that up with a 180 grain, if you were going to shoot 600-1000 I would defenatly use the 180 to keep a tight print but the 168 will make it there just the same with a little loss in accuracy, I have a friend that shoots with me alot with the same rifle as mine and he hand loads 190 grain for his 1 to 11 twist and I beleave they are leaving the barrel at around 2,640 and he shoots 800 yards with the same 4-5 inches I get at 600 yards, he is making me two boxes to play with this weekend I will let you know how that works for me, I thought that seemed a little heavy for a 1 to 11 but the targets don't lie and I watched him do it, I have not had my M1A very long or I could be more informative I do shoot a remington 300 ultramag longrange all the time thats my baby 1000 plus, And for that I use Sierra HPBT at 210 grain with a 1 in 10 twist with incredable accuracy you would just have to see to beleave, that being said that 190 grain for the 1 in 11 twist may be right on the money!!! To tell the truth the .308 kind of petters out at 800 yards to make 1000 yard shots with out doing alot of math you should ues a little more powerful round like the 30-06 or the 300 winmag but if you are talking 800 yards the .308 will do that just fine!!!
     
  12. cpttango30

    cpttango30 New Member

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    The standard twist for a 308 is 1:12".

    This really has little to do with weight but the length and ogive. It just so happens to be that the more a bullet weighs the longer it is. I would go with the Hornady 178gr A-max bullets. Or the Hornady 208gr A-max. Though the 208gr A-max might be a little to long for your twist.
     
  13. matt g

    matt g New Member Supporter

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    Who's standard twist on what .308 chambered rifle?
     
  14. rickrem700

    rickrem700 New Member

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    190 grain at 800 yards with 1 to 11 twist

    Well, the virdict is in, today I shot 20 rounds at 800 yards with my M1A First five shot group a little low and to the left with a eight inch group, it was very windy, and I needed to ajust for a hevyer bullet, (very windy) Farted around with my new 10/22 mag till things setteled down, 2 hours later everything is dead calm and looks like it is going to rain at any minute, fired second five shot group 4 7/8 group with one flyer, at this point I am very happy third 5 shot group 5 1/4 no flyers, still amazed, cannot hardly beleave it!!! did a little more tweaking to my scope, Cleaned bore and ready to shoot last five rounds, starting to rain now, I poped off last five rounds with a light breez and shot a 4 3/8 inch group with 3 rounds darn near touching, I stand corrected a 190 bullet seems to be the sweet spot for the 1 in 11 twist, I was grinning all the way home, I could not wait to tell my buddy how well his hand loads performed in my rifle, If you are interested in the load datta I can tell you that I was useing Federal Brass With CCI primers and a Sierra 190 grain HPBT MATCH KING, I will have to get back to you on the brand of powder and amount of load, But this seems to be the answer, I really did not think this rifle would produce accuracy like this, I am very impressed, I guess it still pays to shop around!!!
     
  15. matt g

    matt g New Member Supporter

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    Sweet, that exactly the sort of info I'm looking for. Thanks Rick!
     
  16. cpttango30

    cpttango30 New Member

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    Every factory rifle I have ever looked up had a 1:12" tiwst.