Determining Perfect Buffer Weight

Discussion in 'AR-15 Discussion' started by monteros, Dec 15, 2012.

  1. monteros

    monteros New Member

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    So, I am doing some reading on buffers atm. I found this over info

    Source: http://www.ar15.com/forums/t_3_118/416283_.html

    I am sure there's other info, and opinions, that's why im posting this :)

    Thoughts?
     
  2. Quentin

    Quentin New Member

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    I agree with the quote except I like my brass to eject about 4 o'clock.

    If you give it enough thought you'll probably come pretty close to the right buffer the first time but most of us end up buying a different weight to test it out.
     
    Last edited: Dec 16, 2012

  3. monteros

    monteros New Member

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    That's kind of what I was thinking. Part of me thinks it might not be bad to have a few I'm my range kit for testing.
     
  4. Sniper03

    Sniper03 Supporting Member Supporter

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    Monteros,

    I agree with Quentin. A rifle that is running correctly which by the way has a good Extractor and Ejector should be kicking the spent rounds out in the 3 - 4 o'clock area of the ejection pattern when running perfectly. And there are a lot of things that determine the buffer weight of a rifle. The size of the gas port and the pressure of the ammunition also have everything to do with selecting the correct buffer. Speaking of ammunition Military Ammunition is of higher pressure than Commercial Ammunition so it can have an effect. And select fire auto weapons are more temperamental than semi auto weapons. As a general rule I have found that weapons with barrels 16" + barrels with collapsible tactical stocks generally have a standard car buffer if the rifle has the correct gas port. Weapons with barrels less than 16 in. usually run best with an H-1 or H-2 Buffer. And weapons with 10" and shorter normally take at least an H-2 and some occasions an H-3. The caution is you can go too heavy which will cause a problem on the other end. There really is no one correct answer it depends on some of the factors above but as stated the 3-4 O'clock is a good rule of thumb to diagnose if the weapon is running well.
    I personally have all four buffers in my armorer kit which I use to diagnose problems. For example if a rifle is having malfunctions due to being over gassed it normally is misdiagnosed in the initial stages. Then the ejection pattern is noted giving us a clue among others that are available if you know what to look for. Such as monitoring the buffer's face, bolt speed, ejection pattern as mentioned. So we put in an H-1 Buffer to attempt to correct it. The weapon now runs much better but we get an occasional hick-up! Go to an H-2 but never jump more than one weight at a time when diagnosing.
    A source for a set of buffers is M&A Parts out of IL.
    03
     
  5. monteros

    monteros New Member

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    Totally appreciate the info!!!! It's my goal to be the most knowledgable I can regarding this weapon system, for myself but more so for my family and friends that are going to use or are already using AR's. Figure if I am competent then we all can be.

    Once again thanks. Going to digest this info and buy my stock and buffer system :)
     
    Last edited: Dec 16, 2012
  6. purehavoc

    purehavoc New Member

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    Just because one carbine barrel will run a h2 doesn't mean the next will , even from the same manufacturer or even function correctly. I have 2 of the same barrels , same build kits . One runs flawless with a 4.2 oz buffer the other runs fine with 4.2 oz and kicks the brass 4 oclock with it but the bolt will not stay open on the last shot so I had to cut 0.2 oz off it to function correctly . So keep that in mind
     
  7. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    My rule of thumb is;
    Carbine, 14.5" - 16" = H buffer
    SBR or Full auto carbine = H2
    Suppressed = H3

    Use this as a starting point. If the gun runs 100% at these levels, leave it alone.

    Some are using super heavy buffers like the 9mm 6 oz buffer or some of the various tungsten buffers made as heavy as 12 oz. IMHO if you need a buffer heavier than the above recommendations, there is something wrong elsewhere in the gun.

    If you feel the need to experiment, go to a golf supply store and get some powdered tungsten. Disassemble the buffer, replace the weights with the powdered tungsten. You can adjust the weight to find the best weight for your gun. For about $20 you can get enough tungsten to make 4 or 5 heavy buffers.
     
  8. Rick1967

    Rick1967 Well-Known Member

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    Hey sniper, nice write up. I learned something. Thank you.

    Rick
     
  9. monteros

    monteros New Member

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    Thanks guys! Great info. Yeah, I noticed while reading, that even H buffers from the same manufacturer can have different weights... I am totally on board with each gun being unique and the potential for tuning it. Great stuff!

    I love the idea about the gold supply shop and powdered tungsten :)
     
  10. Quentin

    Quentin New Member

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    Excellent advice from Sniper, Havoc and 10mm. It is smart to have a selection of buffers available to fine tune an AR. It's been my experience that with a 16" barrel you almost always can go with H over standard weight or even heavier but I've only got much experience over five different ARs.