What are the odds? New Failure I have yet to see.

[Clusterfrack]

My experience as well though I don't shoot reloads. I've had blown primers with Noveske, Geissele, and a smith built Criterion Core barreled upper and at least the last two were symptoms of a larger problem. I've owned BCMs since 2013ish and after owning at least half a dozen barrels and/or complete uppers, that was never an issue. BCM is actually the king of reliability for me with far more sample sizes and less issues than any other manufacturer. I was big sad when a MK2 upper I got in the last two years had significant issues and needed a trip back to the factory but they did handle it better than I could have hoped for.

Back to the OP, I've heard of this once before, I think somewhere in my several page thread on M4C about the Core upper that was giving me hell. Definitely annoying but probably isn't a one time thing. Either your ammo has issues or something is going on in your upper, likely in the chamber between the bolt and barrel extension.

I'm pretty sure @Cdub_NW was using reloads with range pickup brass.

I've started marking any reload that has a "loose" primer seating feel in the press. Then I take all the marked rounds and use a small amount of Krazy glue as a primer sealant. I haven't had any blown primers since.

[Cdub_NW]

To clarify questions: I typically use fired brass pickups from my classes that have been annealed and reloaded with a low-mid charge weight 55gr fmj for all my practice rounds. This particular failure took place with some SPR hand loads that we sourced once fired new brass, cleaned, annealed, etc. Hand thrown charge (well within spec) with 77gr SMK pills. Upper was a complete BCM midweight fluted 5.56 upper with an Omega suppressor. I generally do not push the limits on my reloads to max pressure or max speed nodes to account for rain, weather, etc.

This is the first failure on this upper of any kind over the course of 4 years. This rig has been used primarily as a range rifle to shoot coyotes during the daytime hours. Normally running handloads with either 53gr V-max OR 77gr SMKs. I take this rifle out on camping trips and push the limits of longer ranges often and its been incredibly reliable. That being said, I admittedly went for more of a budget BCG and got a brownells unit when I ordered the upper originally, in hindsight, a BCM BCG would have been the smarter and what I just ordered to replace it with.

[Wake27]

To clarify questions: I typically use fired brass pickups from my classes that have been annealed and reloaded with a low-mid charge weight 55gr fmj for all my practice rounds. This particular failure took place with some SPR hand loads that we sourced once fired new brass, cleaned, annealed, etc. Hand thrown charge (well within spec) with 77gr SMK pills. Upper was a complete BCM midweight fluted 5.56 upper with an Omega suppressor. I generally do not push the limits on my reloads to max pressure or max speed nodes to account for rain, weather, etc.

This is the first failure on this upper of any kind over the course of 4 years. This rig has been used primarily as a range rifle to shoot coyotes during the daytime hours. Normally running handloads with either 53gr V-max OR 77gr SMKs. I take this rifle out on camping trips and push the limits of longer ranges often and its been incredibly reliable. That being said, I admittedly went for more of a budget BCG and got a brownells unit when I ordered the upper originally, in hindsight, a BCM BCG would have been the smarter and what I just ordered to replace it with.

I've always wanted to try their EMW-F barrels. Any idea how many rounds through it? And how many of those with the can? If not a reloading issue (which I know nothing about), I'd guess high backpressure from the Omega but if you've got a lot of rounds through it, that's less likely. My next guess would be that the bolt is wearing and that's causing a headspace issue. I'll be curious to see how this progresses.

[Cdub_NW]

I've always wanted to try their EMW-F barrels. Any idea how many rounds through it? And how many of those with the can? If not a reloading issue (which I know nothing about), I'd guess high backpressure from the Omega but if you've got a lot of rounds through it, that's less likely. My next guess would be that the bolt is wearing and that's causing a headspace issue. I'll be curious to see how this progresses.

I'd guess maybe 1k rounds on this upper, the suppressor has a good amount. I have two Omega's one has been shot out and rebuild by SiCo (first baffle was eroded away) but currently both are in good shape, maybe 6-10K on them each. Rounds kick just forward of 3 o'clock by a degree or two with the can on but no signs of pressure on the brass.

The new BCM BCG arrived and will be testing this weekend to confirm function.

[Wake27]

I'd guess maybe 1k rounds on this upper, the suppressor has a good amount. I have two Omega's one has been shot out and rebuild by SiCo (first baffle was eroded away) but currently both are in good shape, maybe 6-10K on them each. Rounds kick just forward of 3 o'clock by a degree or two with the can on but no signs of pressure on the brass.

The new BCM BCG arrived and will be testing this weekend to confirm function.

Interesting, shouldn’t be having any issues at that round count. Hopefully the BCM BCG takes care of it. The smell alone is magical.

[willie]

I always destroyed any cases with loose primer pockets. There are many here who have fired more ammo than I, but I'll guess that with various weapons I've shot at least 250,000 center fire rounds. Never have I had a popped primer. However, some of my reloads cratered a few. I'm happy to say that I have all my fingers.

[Cdub_NW]

Figured I would post an update to the event. I ordered a new BCM BCG for the rifle and have about 300 rounds through it with zero issues. Same lot of handload rounds as the failure with no subsequent issues. I plan to keep a close eye on the fit of primers on the new round of mass loading and will remove any with loose pockets going forward.