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Author Topic: AR15 ejection pattern?  (Read 596 times)

Roper1911

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AR15 ejection pattern?
« on: December 30, 2016, 09:20:12 PM »
so I'm tuning my AR, trying to get the brass to stop bouncing off the receiver. and the ejection has moved from 4-5 and super energetic (it would hock the brass hard enough to dent the deflector) to about 1:30-2 and rather softly, around 4-5 foot.

current setup is a flat wire spring, H3 buffer (I have all the parts to make it an H1/H2 as well.)

I've found resources that say it's overgassed, undergassed, and perfect.
so what is it really?
North Carolina"it has two fire modes, safe, and most decidedly unsafe"
~Chief Warrant Leon McMurdo. Shilo Mountain Rangers, sixth battalion. Mount Hector School of Military tactics. November 8th 3451.

Yes. When the question is 1911, the answer is "yes". ~HVS

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    ZeroTA

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    Re: AR15 ejection pattern?
    « Reply #1 on: December 30, 2016, 10:18:55 PM »
    Too hard and you run into durability issues. Too soft and you run into reliability issues. As long as it runs your loads and it's not barfing brass out at your feet, you're really gtg. Some people try to make it into one, but it's not an exact science. Yeah, there actually is a lot of physics and math involved if you care to dig into it, but all at matters is how it actually works when you pull the trigger.

    TL,DR: Sounds fine to me.
    I'm not saying you should use an M1A for home defense, but I'm also not saying you shouldn't.

    Mississippi556

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    Re: AR15 ejection pattern?
    « Reply #2 on: December 31, 2016, 08:31:21 PM »
    What ammo are you shooting?  Many things can affect ejection pattern. 

    I always thought the hottest ammo would eject more forward at 1 or 2 o'clock, bouncing hard agsinst the deflector, and the weakest back toward 5 o'clock.  That has been my experience.

    Hot full power 5.56 ammo (like M855 green tip) ejects more forward than milder .223 ammo in my rifles.

    Gas port location and port diameter play a role, too.

    My carbine port 16" barrels are running the standard carbine spring and only a H2 buffer. Ejection and bolt speed seem fine.  I would rather be a little over gassed with hot ammo and know I can reliably cycle everything I shoot.
    Mississippi"When a strong man, fully armed, guards his own palace, his goods are safe"  Words of Jesus, Luke 11:21 (ESV).

    mattitude

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    Re: AR15 ejection pattern?
    « Reply #3 on: January 01, 2017, 11:55:35 AM »
    If your rifle is over-gassed you'll feel it being snappy and/or with a faster running (bolt) speed.  Ejection location doesn't always equate to gas pressure but if it's really beating up your brass or even the deflector then yea it sounds like there is some extra power there.  Adding a heavier buffer & stiffer spring isn't really the best fix as at least one byproduct is extra moving mass which will give you more flip and felt recoil.  I would recommend an adjustable gas block as that's the best way to regulate gas flow and to set up your system to run reliably with whatever ammo you feed it.
    North CarolinaMedically retired Air Force (17 years, 7 months & 25 days)

    Unobtanium

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    Re: AR15 ejection pattern?
    « Reply #4 on: February 10, 2017, 02:38:36 AM »
    so I'm tuning my AR, trying to get the brass to stop bouncing off the receiver. and the ejection has moved from 4-5 and super energetic (it would hock the brass hard enough to dent the deflector) to about 1:30-2 and rather softly, around 4-5 foot.

    current setup is a flat wire spring, H3 buffer (I have all the parts to make it an H1/H2 as well.)

    I've found resources that say it's overgassed, undergassed, and perfect.
    so what is it really?

    Without seeing footage of the weapon being fired, that's difficult to say. This is one of my M4 type rifles, and is a perfect example of a very correctly gassed, sprung, and buffered weapon. M855 is what is being shot.
    Arkansas

    Roper1911

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    Re: AR15 ejection pattern?
    « Reply #5 on: February 10, 2017, 08:09:28 AM »
    After 500 rounds on the new spring she's ejecting around 3:30 and about 5 foot from the rifle. Its regular enough that I could put a bucket on top of the first shots brass and catch the remaining 29 rounds assuming I don't move. It's been there for about 300 rounds now and it's not moving. So I'm guessing that the spring just needed to be shot in.
    North Carolina"it has two fire modes, safe, and most decidedly unsafe"
    ~Chief Warrant Leon McMurdo. Shilo Mountain Rangers, sixth battalion. Mount Hector School of Military tactics. November 8th 3451.

    Yes. When the question is 1911, the answer is "yes". ~HVS

    Mississippi556

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    Re: AR15 ejection pattern?
    « Reply #6 on: March 02, 2017, 09:16:37 PM »
    What ammo are you shooting? 
    Mississippi"When a strong man, fully armed, guards his own palace, his goods are safe"  Words of Jesus, Luke 11:21 (ESV).

    Roper1911

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    Re: AR15 ejection pattern?
    « Reply #7 on: March 02, 2017, 09:41:50 PM »
    PMC brass 5.56. It's ejecting at 3:30 like a clock now.
    North Carolina"it has two fire modes, safe, and most decidedly unsafe"
    ~Chief Warrant Leon McMurdo. Shilo Mountain Rangers, sixth battalion. Mount Hector School of Military tactics. November 8th 3451.

    Yes. When the question is 1911, the answer is "yes". ~HVS

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