223 AR, newly built, fires, will not eject?

[CT10ring]

Hello,
Having a problem with the first AR upper I have built...using my 80% lower.

It fires, but does not eject the case. at all. Side charger.
If I rack the bolt, the fired case ejects, and strips/chambers the next round.

60g Vmax, VVN 135, 23.5g CCI 450 primers, 1X fired Norma brass, fl sized ( shot in another AR w
5.56 nato chamber) approx .002 setback.

I didn't have or try any factory 223. fwiw.

22" Krieger .223 "match" chamber" 1/7.7 - chambered by Krieger

* the tube is centered in the gas key - does not bind
* rifle length gas, melonited gas tube
* gas block installed by me - think it is from WOA. good fit .750" as I recall, not pinned, I clamped
to bbl using allen screws supplied
* JP bolt, A Arms upper /side charger, AA carrier


I tried this same load in another 223 1/8 upper, with the same lower - perfect function.

In looking at the Krieger chamber, it looks well, rough, compared to the other AR.
Could this be the problem, too tight a match chamber? and not very smooth.

Or could my gas block be not centered, too far forward/back, not over the gas hole in bbl?
gas hole in bbl blocked?

any info appreciated.

thx.

 

[Mark M.]

Sounds like you have a gas block issue, I would recheck the alignment on the barrel

 

[geraldgee]

I am guessing the chamber could be moved to the bottom of your list of concerns. I realize Krieger could mess up a chamber, but it’s least likely of every thing you mentioned. Have you verified your buffer and buffer spring are functioning correctly?

You can check if your gas port/tube is clogged by plugging the chamber with a foam ear plug and blowing through the other end. Of course, the assumption is that anything you try will be done safely with an unloaded rifle.

You can determine if your gas block is correctly aligned if the gas tube is in perfect line with the barrel extension pin (12 noon on an assembled upper).

The AR is a simple weapon and you should have little trouble determining the source of your problem.

Please be careful and exercise sound gun safety and good luck.

Gerald

Did you assemble the rifle?

 

[Johnny_V]

This is a one in a million shot, but check your gas key and see if there might be a blown primer in the key. Had this happen to a Bushmaster after the first five shots out of the gun.

 

[TheOtherZilla]

This is a one in a million shot, but check your gas key and see if there might be a blown primer in the key. Had this happen to a Bushmaster after the first five shots out of the gun.

I just had a primer blow and lodge in the bolt on one side between the bolt and upper .... Same thing. Then it happened as I didn't know what was going on. It jammed the bolt. I thought the shell case was stuck. But after finally getting the bolt and shell out I found something laying on the bench. At first I thought a piece of the star broke off the bolt. But on closer inspection it was a mashed primer.. That caused some grief.

 

[CT10ring]

I am guessing the chamber could be moved to the bottom of your list of concerns. I realize Krieger could mess up a chamber, but it’s least likely of every thing you mentioned. Have you verified your buffer and buffer spring are functioning correctly?

Yes, rifle buffer is standard rifle, JP buffer spring. lower - perfect function w another AR upper.

You can check if your gas port/tube is clogged by plugging the chamber with a foam ear plug and blowing through the other end. Of course, the assumption is that anything you try will be done safely with an unloaded rifle.

OK, I'll take the round out of the chamber

You can determine if your gas block is correctly aligned if the gas tube is in perfect line with the barrel extension pin (12 noon on an assembled upper).

visually align / eyeball it it? yes, did that. no dimple on bbl, just slid gas tube in thru lock nut (WOA 15" handguard) and seemed to align perfectly. nothing binding, odd.

The AR is a simple weapon and you should have little trouble determining the source of your problem.

I've shot + loaded many 1000's of AR rounds, never a hiccup. yeah, it's darn basic.
I am guessing : load is too hot, fired brass ( from a generous 5.56 chamber) needs to be re-sized w a small base die.
or tossed. gas block alignment needs to be checked - gas block is misaligned or too far forward. chamber is bit rough - a combination of all.

Please be careful and exercise sound gun safety and good luck.

Thank you.

Gerald

 

[CT10ring]

Sounds like you have a gas block issue, I would recheck the alignment on the barrel

stripping it tomorrow. although in speaking to others while building , it seems that the standard of alignment of gas block is visual? is there a way of checking w a feeler wire thru bbl up thru gas port? I'll measure again- block & bbl gas port hole.

 

[CT10ring]

I just had a primer blow and lodge in the bolt on one side between the bolt and upper .... Same thing. Then it happened as I didn't know what was going on. It jammed the bolt. I thought the shell case was stuck. But after finally getting the bolt and shell out I found something laying on the bench. At first I thought a piece of the star broke off the bolt. But on closer inspection it was a mashed primer.. That caused some grief.

thanks. in my case, jam happened each shot. just stripped & checked bolt, chamber. all good in that regard. I think my loads are too hot & 1X fired brass is oversized from using in a larger AR chamber before. Using cci 450's 1st time - Sierra accuracy load but w 450's - too hot. the primers are very flat.
although the same loads in another AR upper - shot great groups w perfect function.

 

[TheOtherZilla]

I had that problem too.. These days I re-size with a small base die. And I make sure it is tight in the press.. Yes I let it gt loose and didn't notice. Didn't take much..

 

[simo hayha]

you may need a spacer between gas block and the shoulder on the barrel....

 

[Tommie]

Run some factory .223 ammo through it and see what happens.

 

[nmkid]

I recently did my first AR build. As suggested by geraldgee I also used an ear plug in the chamber. First I sprayed a good shot of spray cleaner in the barrel, plugged the chamber and stuck an air hose to the end of the barrel. I got a good, small dose of spray out of the gas plug. So, I figured my gas plug was more or less properly aligned. No ejection problem.

 

[Rsadams]

It's the gas block... Recheck that it's over the port correctly... Most barrel ports are oversized these days so there is plenty of pressure... If the gas tube is in the gas key like it should be then it has to be the gas block not centered over the port on the barrel....

 

[243winxb]

gas hole in bbl blocked?

Check diameter.

 

[shoot4fun]

I agree that you have a gas block/port alignment issue. That is the most prevalent issue when building without a pinned gas block.
Trouble is, just about all after-market bas blocks are installed with set screws.

 

[CT10ring]

It's the gas block... Recheck that it's over the port correctly... Most barrel ports are oversized these days so there is plenty of pressure... If the gas tube is in the gas key like it should be then it has to be the gas block not centered over the port on the barrel....

yup, I'm taking it apart & re-measuring hole/block alignment etc.

 

[CT10ring]

I agree that you have a gas block/port alignment issue. That is the most prevalent issue when building without a pinned gas block.
Trouble is, just about all after-market bas blocks are installed with set screws.

yes, these are set screws, WOA block. I have other blocks, will check bbl shoulder to hole alignment with them also.
just thought I'd ask here re info & appreciated.

 

[searcher]

With proper ammo, most failure to load problems seem to come from the bolt carrier not being pushed back far enough. If your gas block is aligned, replace your buffer spring with the spring from your other A/R. That may show you the spring you have is too heavy for the load. If that doesn't work, I'd replace the spring with a
Wolff Reduced Power spring. I'd not increase your powder if you are within 10% of max - as that is not the problem. Another trick on a new rig is to get your bolt carrier and remove the firing pin and cam. keep the bolt in it. push the bolt in and out of the bolt carrier about a hundred times with no lubrication on the bolt or in the carrier. This will take the micro-burrs off the gas rings on the bolt to allow it to slide easier. A lot of new A/R's have cycling problems, especially with light loads or springs heavier than the load allows for proper operation - until they "break in" Then lube, reassemble and give it another try after ensuring all other heavy friction points on the firearm are also lubed.

 

[CT10ring]

With proper ammo, most failure to load problems seem to come from the bolt carrier not being pushed back far enough. If your gas block is aligned, replace your buffer spring with the spring from your other A/R. That may show you the spring you have is too heavy for the load. If that doesn't work, I'd replace the spring with a
Wolff Reduced Power spring. I'd not increase your powder if you are within 10% of max - as that is not the problem. Another trick on a new rig is to get your bolt carrier and remove the firing pin and cam. keep the bolt in it. push the bolt in and out of the bolt carrier about a hundred times with no lubrication on the bolt or in the carrier. This will take the micro-burrs off the gas rings on the bolt to allow it to slide easier. A lot of new A/R's have cycling problems, especially with light loads or springs heavier than the load allows for proper operation - until they "break in" Then lube, reassemble and give it another try after ensuring all other heavy friction points on the firearm are also lubed.

thx, I used the same lower on 2 uppers - one I built (as posted - bolt remained closed after firing) & another 223 AR built by Sabreco (which did + has always functioned perfectly). So the buffer spring (JP rifle length spring) and buffer (basic rifle length /Brownells) are good. As is the lower. I'll try the cycling/deburring tip. Is is possible that my load is so hot that the brass is stuck to a kinda rough chamber ? - like a bolt gun, when you have to uh, tap/whack the bolt to extract the brass? feels like that may be the case. Obviously I'll make some changes and test w factory ammo, etc.
all info posted appreciated.

 

[CT10ring]

This is a one in a million shot, but check your gas key and see if there might be a blown primer in the key. Had this happen to a Bushmaster after the first five shots out of the gun.

checked, all good there.