Ar15 ejection problem

[SudoNoob]

Hey guys, I built an AR15 (lower piece by piece & upper all together) it's chambered in 5.56 and it's direct impingement. When I shoot .223, it ejects fine but when I shoot 5.56, the BCG only goes back about half an inch so I have to manually cycle the weapon every shot. Any idea what's going on? I appreciate any suggestions/input.

[Kwikvette]

Have you tried other types of ammunition?

Could be limited to that specific batch of 5.56 you're shooting.

[SudoNoob]

Have you tried other types of ammunition?

Could be limited to that specific batch of 5.56 you're shooting.

Not yet. I only had one type of 5.56 when I was shooting but I'll give it a shot to see if that works.

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[hunterb]

Are you sure it's a 5.56mm barrel? Did you put the upper together or did a gunsmith? Got go/no go gauges?

What brand of barrel? Barrel length? Carbine or middy or rifle gas?

Also, #1 is try different ammo as suggested above, and different magazines too.

Someone like Randall will be along eventually with more knowledge for you.

[SudoNoob]

Are you sure it's a 5.56mm barrel? Did you put the upper together or did a gunsmith? Got go/no go gauges?

What brand of barrel? Barrel length? Carbine or middy or rifle gas?

Also, #1 is try different ammo as suggested above, and different magazines too.

Someone like Randall will be along eventually with more knowledge for you.

This is the upper I got:

https://www.specopmfg.com/56223-ar15-assembled-uppers/3101-specop-ulk15v6-556-upper-half.html

With this BCG:

https://www.specopmfg.com/bolt-carrier-bcgs/3072-specop-mfg-556-nib-hptmpi-full-auto-bolt-carrier.html

ADDITIONAL INFORMATION
Manufacturing # :SKU SPM-ULK15V6-556
Restricted Shipping:No
Caliber:5.56mm NATO
Gas System:Carbine
Barrel Length:16"
Profile:M4
Product Weight:3.2 lbs
Manufacturer:SpecOp MFG

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[kcheung2]

Just a WAG, but did you shoot a box of .223 first, and then switch over to 5.56?

[baih777]

What brand 556 ?

[SudoNoob]

Just a WAG, but did you shoot a box of .223 first, and then switch over to 5.56?

Yes

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[SudoNoob]

What brand 556 ?

Federal American Eagle

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[hunterb]

Hmmm. BCG looks legit and quality specs. Upper is lower priced but looks very nice...

Are you using the correct carbine buffer tube, buffer weight and buffer spring?

[the Scholar]

Federal American Eagle

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Did you shoot them in the same session or did you clean the rifle in between? If you cleaned it, did you rotate the bolt with the ejector on the wrong side?

[CouchOperator]

Have you since fired it since putting the ammo that was causing issues through it? Results? Im suspecting possible gas block drift

[Calico1404]

223 seems to work, 556 the bolt only goes back an inch?

Calling ammo out on this one if your BCG is in fine shape and gas tube is solid.

[SudoNoob]

Did you shoot them in the same session or did you clean the rifle in between? If you cleaned it, did you rotate the bolt with the ejector on the wrong side?

Shot in same session.

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[SudoNoob]

Have you since fired it since putting the ammo that was causing issues through it? Results? Im suspecting possible gas block drift

I went from .223 (no problem) to 5.56 (ejection problem) then back to .223 (no problem)

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