So, AR15 guru's...

[MegaFan]

The guy said he measured my barrel and it was 0.081... sounds like its fine?

Sounds like it. Might still be worth a call to Faxon to verify the proper size or to see if others have needed a slight increase. They should know if this is a common issue. I keep various weight buffers, have dozens of spare BCGs, extra springs, etc., and the drilled port was my only successful fix, plus it was easy to do. I also keep spare gas blocks, including adjustable ones that could have tamed mine if the hole had been too aggressive. When you have numerous AR pistols, it is good to have spares of "everything" ready and available for testing.

 

[opps]

I like Faxon and BA barrels. May have one in a SBR - have to look. Always run H buffers with carbine gas systems. Learned this from Colt rifles 20 years ago. Also have adjustable gas blocks on some systems for suppressor use.
I have found American often under powered - sorta like what can happen with Winchester white box. No idea on Norma. Never ran it.
Hope the heavier buffer helps.
Also never run steel case Russian - most of my rifles hate it and it usually is weak.
Most gas bocks now have a larger opening where it meets the barrel port to allow for slight misalignment fore and aft. They take into account not having the handguard end cap with a rail.

 

[cmshoot]

Well, I already have a light buffer, the one it had issues with at 2 7/8 oz... I am gonna try the H2 buffer shortly after my meeting ends and I can run down to the range...

I have a Daniel Defense BCG I can take with me, and I will take the buffer out of my rifle that I know works in that gun... that way I have two buffers to try, both BCG's, etc...

I will bring the buffer, buffer spring and BCG from my other gun with me. One thing I noticed is that the spring in the pistol is about 3/4 of an inch longer than the other one, and pulling back the charging handle, the pistol seems stiffer. Not too stiff, and maybe that is because the other one has more rounds through it so it is more worn in... But I can feel a difference. The guys at the range felt it and said it was fine and not too stiff. giggity...

Just making sure you have the correct buffer spring. Buffer spring measurements:
Carbine: 10 1/16” - 11 1/4”
Rifle: 11 3/4” - 13 1/2”

Those lengths are when brand new, they’ll contract a bit after use and/or load.

 

[cmshoot]

The guy said he measured my barrel and it was 0.081... sounds like its fine?

That gas port should be fine for that barrel length. If it’s undergassed, the gas port isn’t the culprit.

When I said undergassed, what I should have said was undergassed and/or oversprung. They’ll act the same.

 

[SirBannedAlot]

Well, the H2 buffer seems to have solved it. I took 100 rounds of 3 different brands of .223 as well as a 20 round box of American Eagle 5.56 and with the heavier buffer it ran everything flawless. Not a single hiccup of any kind. Did slow shooting, did doubletaps, did a mag dump to get it good and hot... Runs awesome now.

Glad it was something simple! $40 fix...

Thanks gents!

 

[gregmanz]

Well, the H2 buffer seems to have solved it. I took 100 rounds of 3 different brands of .223 as well as a 20 round box of American Eagle 5.56 and with the heavier buffer it ran everything flawless. Not a single hiccup of any kind. Did slow shooting, did doubletaps, did a mag dump to get it good and hot... Runs awesome now.

Glad it was something simple! $40 fix...

Thanks gents!

That makes no sense. It goes against your issue. Perhaps taking it apart and putting it back together did something. A heavier buffer shouldn’t fix an issue with a lower pressure round. But In general an ar that’s working correctly, with .223 should cycle an h2 or h3 buffer.


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[cmshoot]

Well, the H2 buffer seems to have solved it. I took 100 rounds of 3 different brands of .223 as well as a 20 round box of American Eagle 5.56 and with the heavier buffer it ran everything flawless. Not a single hiccup of any kind. Did slow shooting, did doubletaps, did a mag dump to get it good and hot... Runs awesome now.

Glad it was something simple! $40 fix...

Thanks gents!

That was a weird one for sure. Anyways, glad it’s back up and running!

 

[SirBannedAlot]

That makes no sense. It goes against your issue. Perhaps taking it apart and putting it back together did something. A heavier buffer shouldn’t fix an issue with a lower pressure round. But In general an ar that’s working correctly, with .223 should cycle an h2 or h3 buffer.


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It was explained to me like this... Take a 2 liter bottle of Coke, and remove the cap. Put your thumb LIGHTLY over the opening, and shake it up. Stuff comes out quickly but more of a sploosh... Now take a bottle and put your thumb over it tighter and shake it... Your thumb will hold it back a little longer, but it will push past your thumb and when it does it will be under more pressure.

Not an exact analogy, but I think you get the point... We increased the... duration... for lack of a better word...

By delaying the action due to a higher inertia that must be overcome... the object at rest wants to stay at rest... Even for a few milliseconds... This allows more pressure to build in the gas tube and gas key, so that when inertia is overcome and it flies back, it does so faster... or at least harder, because the heavier buffer, once moving... has more momentum... an object in motion wants to stay in motion...

I mean, it could have been taking it apart and putting it back together. Next time I hit the range, I will bring the lighter buffer and see what happens... That will tell us if we shook something loose or lined things up better, or if it was the heavier buffer.

But in the end, it ran like a champ with all 4 brands of ammo I tossed in it... two of them were the .223 boxes that yesterday were giving me headaches...

 

[SirBannedAlot]

I don't know if I explained it well, so here is another way to look at it...

With that 2 7/8 oz buffer, it flew back fast, maybe too fast. That bolt carrier only has a short duration where there is pressure in the gas tube... once it slides back what, 1/4 of an inch, all that pressure blows everywhere else... If it comes out of batter too soon, there may not have been enough pressure in there to achieve the needed velocity to cycle properly.

5.56 obvious has more pressure, so it was enough...

Now that we slowed down the action that tiny bit, it stays in battery longer so pressure builds up to a higher level so that when it does send it, it's got the energy to do what it needs to...

 

[jeep78]

If it ain't broke now, no need to fix it any more.