Dead Gun! Thoughts?

[ssc]

Was shooting an LMT. Fire 4 rounds and the 5th, the trigger won't move. Felt like the safety was on, but it wasn't. I clear the gun and push out takedown pin. The hammer is cocked and the trigger is frozen. I can't get the hammer forward. I suspect what the problem is, but can't see anything in the lower.
I get it home and pull the upper. I again inspect the lower but can't see anything that would jam the action.

I remove the hammer pin and hammer stays in place. I use a plastic hammer and punch and the hammer "pops" out. The trigger has a little movement now but not what it should have. I pull the trigger and sure enough, up against the back wall of the receiver, below the safety, wedged beneath the end of the trigger bar is a fired primer. That was what I suspected. I have heard of this, but this is a first for me. Called a buddy who is an armorer for a large dept. He said he has seen it a few times. So, I figure it is just what it is?

I was thinking about this issue and thought "Why don't they mill a bit out of the receiver so if any items get deposited it has some free space behind the trigger bar?" I decide to inspect different lowers. LMT and BCM look identical. Colt is a bit different but still has the same wall. Then I inspected one of my Sionics lowers and it is exactly what I was thinking. First there is substantially more room behind the trigger and also, it would have been easy to see the primer and remove it. I will attempt to attach some pictures. I hope I do it correctly and everyone can see what I am talking about. I wonder if this is the reason sionics milled their lower? Thoughts? Thoughts on this situation? Does it make sense? Makes me rethink grabbing an AR in an emergency without having a sidearm to transition to. Thoughts?

Pictures show LMT with trigger, then Sionics with trigger and then LMT with trigger removed.
IMG_3594.jpgIMG_3592.jpgIMG_3593.jpg

[Disciple]

Were you using ammunition with staked primers? The Sionics modification is interesting; are there more brands like this?

[HKGuns]

I’m just speculating, as I am not a lower expert.

Perhaps that filled gap in the LMT adds some rigidity to the lower?

[ssc]

I was shooting reloads. I have looked at the following lowers: Sionics, BCM, LMT, Colt, Bushmaster, CMMP and a few others. So far, only Sionics has the cut. I doubt it adds much rigidity, but I am speculating as well. Perhaps I can ask everyone to look at their lowers to see if anyone else has the Sionics "cut."

I will probably call Sionics for their input. Being retired, I think I have too much time on my hands. However, I see no downside to the sionics cut. There is much more visibility. I think it is a better mousetrap???

Cheers, Steve

[Disciple]

Makes me rethink grabbing an AR in an emergency without having a sidearm to transition to. Thoughts?

Many flavors of .223 and 5.56 come with crimped or staked primers so why not use one of those in a defensive gun? I don't think any of my 6.5 Grendel ammunition has crimped primers however.

[grizzman]

I never noticed my Sionics being different. I will check it out after work.


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[georgeib]

In 40 years of shooting I have personally only seen popped primers happen with reloads.

[MSW]

I’ve read about it & knew guys who used these, when they were available:

https://www.midwayusa.com/product/1003349235

[DG23]

In 40 years of shooting I have personally only seen popped primers happen with reloads.

Can happen to ammo like M193 fairly easily when firing in a .223 chamber. Depends on how 'tight' the chamber is but it does happen.

Popped primers, case mouths ripped off or split to hell, etc. Great way to ruin what 'could' have been perfectly good once fired brass to the point where it is garbage.

[DG23]

I’ve read about it & knew guys who used these, when they were available:

https://www.midwayusa.com/product/1003349235

Not bashing them cause I do have and like a lot of their older stuff (back from their early years) but it is fitting that they would make and sell such a thing cause their .223 chambers back then were tighter than hell.

Have sent more than a couple off to CLE to be rechambered so they do NOT make mil spec ammo puke primers so easily...

No issues at all with their chambers or popped primers IF shooting the proper ammo out of them.