Primer popping out

[DaveyC]

I just finished my first AR build and it turned out pretty great. I took it out and fired a single shot to test function. I picked up the brass and the primer was bubbled out. I’m curious what might be causing it and how dangerous it could be. My barrel is a heavy .223 Wylde from Wilson Combat. Ammo was factory Hornady .223 Rem. 55 grain V-Max.

[Berncly]

Try different ammo and compare the expended primers.

[JenniferG]

Primers popping out is an indicator of over pressure. Make sure you ammo is matched to your chamber. Over pressure can occur if the bullet itself is touching up against the rifling when the round is chambered indicating that your round is either incorrect for the chamber or the round itself is out of spec for cartridge length. There must be a certain amount of leade in the chamber for the round to fire correctly. This has been a problem with people using 5.56 x 45 NATO rounds in the chambers of firearms that are designed for .223 rounds. I don't have the specs for .223 Wylde but compare the specs yourself to see if they coincide and can be interchangeably used with .223.

[Bang]

Wylde chamber is a little more ample than a stock .223 chamber, making contacting the lands with factory .223 ammo unlikely. Sounds more like excessive headspace, which will allow the primer to back out some. Have you checked the chamber/bolt with headspace gauges? Tried a fired case in a Wilson cartridge case gauge?

[DaveyC]

Wylde chamber is a little more ample than a stock .223 chamber, making contacting the lands with factory .223 ammo unlikely. Sounds more like excessive headspace, which will allow the primer to back out some. Have you checked the chamber/bolt with headspace gauges? Tried a fired case in a Wilson cartridge case gauge?

Yes, I checked headspace with Go and No Go gauges using my bolt. image1.jpgimage2.jpg

[Hawk]

Yes, I checked headspace with Go and No Go gauges using my bolt. image1.jpgimage2.jpg

+ 1 on to much head space.
FYI - You need to remove the extractor from the bolt to properly check head space. Did you purchase the barrel and the bolt as a matched set? If not, I suspect one is out of spec.

[DaveyC]

+ 1 on to much head space.
FYI - You need to remove the extractor from the bolt to properly check head space. Did you purchase the barrel and the bolt as a matched set? If not, I suspect one is out of spec.

It was not a matched set. I would have purchased if it was an option.

[Bang]

https://www.youtube.com/watch?v=pcVh-XBOLKg

[Gunplummer]

I have never seen anything like that. Amazing it did not rupture the primer.

[cdi]

AR pattern rifles are known to blow primers out of the pocket from time to time.
I have had it happen a few times over the years. The loose primer usually falls into the trigger assembly and causes all kinds of mischief.

I have only seen this with commercial ammo, without the crimp that comes with military ammo.
I see you checked the headspace but I don't see what the result was-
I think it was an ammo failure at this point. I would try firing 5.56 military ammo and see if it recurs.