Bad chamber 223

Snuby642

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Not going to bash a popular vendor or brand since a return is possible.

But damn, had problems short stroking, no lockback jams.
Increadably near 1 1/4 moa on the test shots with factory rounds.

After picking every detail apart in this re barrel of a carbine found a defect finally.

Saved some brass from being mixed with others and this time made sure it came from my gun.
First fired 1.460 to shoulder!
The rest of our gas guns all come in at 1.4635, 1.4630 and random range brass is 1.4635 to 1.464 .

So 0.0035 short but factory brass being short as it is chambered and shot.

So I suppose this would contribute to the problems I had.
My first short chamber so no referance.

Eye problems and surgery recovery between assembly and being cleared to shoot,
evedently headspace got lost in the 4 month wait.

Will see if company upholds waranty, reputable place I expect they will.
 

redneckbmxer24

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Ohh and your chamber is not “short” but it’s not a giant sloppy chamber either. 1.460” is above SAAMI minimum for both 223 and 5.56 chamber specs.
 

Snuby642

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Replacement barrel, 2 different bcg's that come in spec on other barrels.
 

Constructor

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Not going to bash a popular vendor or brand since a return is possible.

But damn, had problems short stroking, no lockback jams.
Increadably near 1 1/4 moa on the test shots with factory rounds.

After picking every detail apart in this re barrel of a carbine found a defect finally.

Saved some brass from being mixed with others and this time made sure it came from my gun.
First fired 1.460 to shoulder!
The rest of our gas guns all come in at 1.4635, 1.4630 and random range brass is 1.4635 to 1.464 .

So 0.0035 short but factory brass being short as it is chambered and shot.

So I suppose this would contribute to the problems I had.
My first short chamber so no referance.

Eye problems and surgery recovery between assembly and being cleared to shoot,
evedently headspace got lost in the 4 month wait.

Will see if company upholds waranty, reputable place I expect they will.
Short usually isn't a problem as long as the cartridges chamber. A long chamber will destroy accuracy.
Not locking back(short stroking) could be several things, gas leaks, gas block not aligned, wrong buffer or spring or a small gas port.
"Jams" could also be because of the short stroking.
 

redneckbmxer24

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Replacement barrel, 2 different bcg's that come in spec on other barrels.
If the fired brass is coming out 1.460” then the headspace is still in spec with this tube as well.

How was it assembled? What other parts did you use? Is it a premium tier barrel (feel free to PM me the manufacturer if you don’t want to post publicly)? What ammo did you try? What optic are you using? Who is the rifle supported? What gas system parts and who installed them?
 

Snuby642

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Nato go gauge 1.436
223 go gauge 1.464
Saami min shoulder 1.4636

Think you were looking at cartridge.
 

Snuby642

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Measured at .330 datum.
All parts vetted with other uppers and or barrels.
Shooting groups slowly it heats and gets malfunctions.
When I pull it down I will measure gas port.

Second bcg was same result and brass was .0005 different.
 
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redneckbmxer24

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You need to measure your brass to the datum line using a .330" bushing. That's where headspace is measured.

Brass also doesn't just magically grow to exactly the chamber dimensions, there is spring back. Based on the AR chambers I've measured and fired brass I would say with complete confidence that your chamber is in spec towards the minimum side which is a good thing and I seriously doubt has anything to do with the issues you're having. Take 5 rounds of ammo that measure smaller than 1.460" to the datum line, number them, record them, and fire them one at a time measuring after. If the brass is growing at all then your chamber isn't the problem.

If your headspace was short you'd have issues with rounds going into battery and you'd be seeing pressure signs, none of the issues you're describing. It 100% sounds like an assembly issues whether gas system isn't aligned, or parts aren't working with one another.
 

Steel head

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You need to measure your brass to the datum line using a .330" bushing. That's where headspace is measured.

Brass also doesn't just magically grow to exactly the chamber dimensions, there is spring back. Based on the AR chambers I've measured and fired brass I would say with complete confidence that your chamber is in spec towards the minimum side which is a good thing and I seriously doubt has anything to do with the issues you're having. Take 5 rounds of ammo that measure smaller than 1.460" to the datum line, number them, record them, and fire them one at a time measuring after. If the brass is growing at all then your chamber isn't the problem.

If your headspace was short you'd have issues with rounds going into battery and you'd be seeing pressure signs, none of the issues you're describing. It 100% sounds like an assembly issues whether gas system isn't aligned, or parts aren't working with one another.
This.
I’d check for a misaligned or leaky gas block and possibly your gas rings.
 

Snuby642

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Bolt gas rings properly offset.
There was a couple of failure to chamber and after super clean and lube will go about 20 rounds. Figured that might wear in but not with that chamber. No evidence of gas leak found.

Again 1.460 is an ammo minimum, not a chamber minimum.
Not all ammo is going to be the minimum and would not fit in this chamber.
None of your go gauges would fit in this chamber.
 

redneckbmxer24

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Again 1.460 is an ammo minimum, not a chamber minimum.
Not all ammo is going to be the minimum and would not fit in this chamber.
None of your go gauges would fit in this chamber.
What don't you get about as long as it's shorter than the chamber dimensions that is doesn't matter?

I literally measure the headspace of 10 rounds every time I get a lot of ammo and I have seen ammo over SAAMI minimum chamber length exactly one time and it was on Barnes 6mm Creedmoor 95gr LRX ammo. Both the initial few boxes and the replacements measured .003" over SAAMI min chamber and were tight chambering in my Fix with Proof barrel that was headspaced .002" over SAAMI min (measured with a case using the scotch tape method, not guessing based on fired cases).

Most factory ammo is .003-.005" short of SAAMI minimum chamber but I've also seen it way shorter than that. Only seen it over once as noted above.

You're making a wild assumption by deciding the barrel/headspace is the problem when every symptom you're having indicates that it is not the case. You also still haven't stated what other parts you used, or how it was assembled.
 

Snuby642

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Tell us again what a 223 / 5.56 chamber minimum is you can look it up at saami.org .

Get over it.
 

Steel head

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Bolt gas rings properly offset.
There was a couple of failure to chamber and after super clean and lube will go about 20 rounds. Figured that might wear in but not with that chamber. No evidence of gas leak found.

Again 1.460 is an ammo minimum, not a chamber minimum.
Not all ammo is going to be the minimum and would not fit in this chamber.
None of your go gauges would fit in this chamber.
If a go gauge doesn’t fit then you probably have issues.
what go gauge are you using?
 

Snuby642

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Ohh and your chamber is not “short” but it’s not a giant sloppy chamber either. 1.460” is above SAAMI minimum for both 223 and 5.56 chamber specs.

Coming from someone that can't comprehend a saami spec.

Lmao
 

supercorndogs

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A comparator is called a compactor for a reason. .0035 is the thickness of your hair.

Has hit failed to close on a headspace gauge? You can not measure your brass to accurately measure your chamber. It does not work that way. Your brass could have easily been .001 smaller than the chamber then .002 smaller after spring back.

It wouldn't be hard for your calipers to be .001-.003 off.
 
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redneckbmxer24

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Coming from someone that can't comprehend a saami spec.

Lmao

1.4666" - .007" = 1.4596" for ammo.

You have not even properly measured your chamber and you don't understand the fact that brass does not grow to exactly what the chamber is because there is spring back, especially on brass that is growing a lot when fired, it will spring back even more. Even on very high quality brass that has been fired multiple times in the same and properly annealed I have typically seen .001" spring back based on what the chamber actually measures using the scotch tape method.

So, try measuring your chamber instead of deciding that something that can't even cause the issues you are having is doing it. I'm not the only one here telling you that you're wrong.
 

Snuby642

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I fully understand there is about .001 springback in there as well as is used in neck only sizing.

But the whole place uses the fire formed round measurement for reloading.

223 / 5.56 running at 3200 fps is fully formed less the small setback.
 

redneckbmxer24

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I get not putting a vendor on blast, but why won't you post the list of the rest of the parts as well as how it was assembled and what you've done to verify other than swapping a BCG.

The only thing swapping BCG's tells me is that it is most likely not a gas ring issue, and definitely not a gas ring issue if they function in other rifles. Your symptoms also tell me that it is not a chamber issue.
 

Snuby642

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You still have not found the chamber spec? It's on the same page.

3 diffrent calipers one with a meteorology services sticker on it.

1.4636 will not chamber.

This was found inadvertently while recording fired brass for notes I keep for each barrel.

My ar tools are accross town in the reloading / gunsmith room or I would have the only thing left unturned measured (the gas hole in the barrel) but that won't fix a chamber issue will it.
 

redneckbmxer24

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You still have not found the chamber spec? It's on the same page.

3 diffrent calipers one with a meteorology services sticker on it.

1.4636 will not chamber.

This was found inadvertently while recording fired brass for notes I keep for each barrel.
I'm aware that the chamber specs are on the same page.

Am I reading it correctly that right that a piece of fired brass that measures 1.4636" that was fired in an entirely different chambers is what you're using as a chamber gauge?
 

Snuby642

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I find this sort of funny.

Everybody seems to be defending this barrel and making me the weak link in this process .

If I had outted the barrel maker you would have all been 180 out on this thread.

Grandkid whatch so my wife can go shooting is slowing this down today.
 

redneckbmxer24

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I find this sort of funny.

Everybody seems to be defending this barrel and making me the weak link in this process .

If I had outted the barrel maker you would have all been 180 out on this thread.

Grandkid whatch so my wife can go shooting is slowing this down today.

That makes more than a few of us apparently. What's the point of this thread? You aren't answering any of my questions about what you've done to troubleshoot, what other parts were used, how it was assembled, who assembled it, how the gas system is aligned or anything except now how you measured headspace with a flawed method using a case from a different rifle (an assumption based on your statement and then ignoring me again when I asked).

Do you want our help fixing your problem or do you want us to lie to you and agree that it must be the barrel while you chase your tail going after what it's more than likely not?

If that's what everybody is saying then maybe you should consider that it might just possibly be the case.

If you want to fix your gun there are a lot of people on here that would help you do it.
 

whatsupdoc

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You still have not found the chamber spec? It's on the same page.

3 diffrent calipers one with a meteorology services sticker on it.

1.4636 will not chamber.

This was found inadvertently while recording fired brass for notes I keep for each barrel.

My ar tools are accross town in the reloading / gunsmith room or I would have the only thing left unturned measured (the gas hole in the barrel) but that won't fix a chamber issue will it.

I asked you previously how you came to your measurement, you replied "Measured at .330 datum" are you using a Hornady comparator?
The measurements you get with a BS caliper and a comparator DO NOT accurately represent the saami datum dimensions.
Read the above sentence twice.

If you have a headspace gauge see if your comparator setup gives you the same dimension as marked on the headspage gauge.
It will not.

The barrel may have an issue but if the factory case fully seats in the chamber the .003 headspace really should not make a difference.
Also a shorter chamber would yield higher pressures, what you describe short stroking and failure to lock bolt back typically is a gas issue.
 

Snuby642

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So you people are so smart.
You failed to bet me on the headspace.

It passed. I would have bet against it.

Now I have to get out a tub and boil some water to get my rocksetted can adapter off so I can dissasemble the hand gaurd.
No leaks visable so down to alignment (still looks good), clogged or missdrilled?

If my brass is going to be 3 thousand different than the 4 other 223 ar's that may mess up my handloads accuracy not that I have tested them in this yet.

If I remember they are set at 1.459

20200123_135456.jpg20200123_135402.jpg

So not done but very few things left to eliminate.

Same bolt same ammo diffrent barrel cant find the .0035 difference.

Snuby642 was wrong again.
 

redneckbmxer24

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Imagine that, something that couldn't have been the issue, wasn't the issue. Now that we're looking at this with some open mindedness, how about the full spec list and process you used putting it together?
 

Snuby642

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Well almost all tools across town to disasemble ar.

So will start build list but some details may be lost in time as this ar has been around long enough to wear out the last BRO barrel.

Top down.

Burris 6.5x20 scope on a Burris pepr mount.
YHM upper and lower, upper newly assembled this barrel.
Magpull stock
BCM grip, too forward for me.
YHM forearm / barrel nut and close out plate spector lenght , at the time good stuff.
Carbine length gas, standard gas block
NM trigger reworked / polished 2- 2 1/2 smooth.
BCG brownells upgrade from stock cant find details.
AAC flash hider adapter
Barrel Stoner heavy fluted. Laugh if you want but it's looking 1- 1 1/2moa with factory rounds between malfunctions and was cheeeeeap.
I have to refill my sand bags as the polyfill is too mushy.

The last stoner barrel I puchased was a 6.5g running moa and just under with Hornady sst 123 factory ammo.

I need to get this carbine back to 1 moa off the bench / stand and reliable at 100 yards.

I use it for culling / pest control, it is a requirement.
I have other stuff to shoot, 308,270,300blk,243,6.5, but need this to perform at 1 moa.
 

Snuby642

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On a side note.

I want to thank everybody for beating me down, the education and generally putting up with my dumb ass.

My wife normally takes care of that but Thursday's she runs a rimfire rifle leage and is stretched a little thin so I know she appreciates it as well.

Cheap mansitting at twice the price.
 

redneckbmxer24

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I wouldn't pull the entire gun apart if you're confident the barrel nut was properly torqued.

I would start at the gas system, you shouldn't have to pull more than the hand guard to evaluate it. Start by finding TDC of your barrel and make sure your gas port is TDC too. Then use a straight edge down the middle of the barrel on top to put an alignment mark on the shoulder just behind where the gas block sits to indicate the center of the gas block. Then you need to do the same on the rear of the gas block based on the port so you can clock them together. Then find the distance off the shoulder to the center of the gas port, and do the same off the rear of the gas block to find distance to the center of the hole in it. Figure what the difference is between the two and you can use feeler gauges between the gas block and shoulder to set the correct distance and get everything centered up.

That's the first thing I would try.
 

Snuby642

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Dissasemble and inspect of gas block position and gas port.

Port is 1/16 + diameter, could not find precision number drills to try. Resources found said 1/16 is standard for carbine gassers.

Carbon fowling confirms gas block was centered and no leaks / obstructions found.
Guess bcg coming apart for second inspection.

20200127_183711.jpg
.20200127_183711.jpg
Black on outside of blocks footprint was marker for measuring, was clear.
 

Greg Langelius *

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Like you, I'm getting used to AR Stoner barrels (223/5.56, and 6.5G).

For me, they're working, and all of my cycling issues have been due to handloads and improperly headspaced dies. Factory ammo (USGI, Bernaul, PPU, and IMI) has not produced any cycling issues for me; but I still do a plunk test in the case gauge, anyway. I think it helps to get that little bit of extra assurance.

I found the actual answers by using Cartridge Length Gauges. If you don't have one for this chambering; I'd get one soon, regardless of how this specific, current issue turned out.

For me, having headspace gauges for my AR's seems like a redundancy. All of mine use bolts and barrel assemblies matched from the same makers. If that's wrong then there'd be a lot more of this sort of thing being reported, I reckon.

Greg
 
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