Why such a soft primer strike?

[Cannonman]

You guys have just been the best and genuine with the help, assistance and education. Thanks. I went out to check some of the stuff suggested and then this. Put one round in the AR 10, .308. Plan is to start adjusting the gas block. It seems to be working. I can watch and see how much more the bolt is traveling while giving it more gas. Then nothing? I'm manually charging the round. Or pulling the charging handle back, let it go, it strips the single round into battery. Pull trigger and "click:. Nothing but a soft dimple on the primer. Hope you don't mind spending a bit more time with you guys. I hope to get a video of what I'm doing. A pic is worth a thousand words. This is frustrating but i can't tell you how much enjoyment it's been to have your collective minds looking over my shoulder. Thanks guys!

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[No_Regerts]

Is the firing pin/channel clean and free of lubricant?

 

[Stomper]

If you installed the lower parts kit yourself, make sure the hammer spring is installed correctly. It is easy to put those in "backwards" if you're not paying attention. If it's installed correctly, it could just be a weak spring.

 

[arrowshooter]

So it went bang.....bang.....bang.....then nada? As mentioned firing pin cleanliness, and springs (also mentioned in your last thread). Posting good clean pictures is your friend, videos not so much. Start with the primers, then pull your BCG and take one of the bolt face with the bolt pushed in and firing pin pushed forward showing the firing pin protrusion, then pull your hammer and take a side view with the spring legs down. Another would be of the BCG in battery with a round in the chamber, but this is best done at the range.

Make sure that your firing pin is not bent.

 

[titsonritz]

 

[mhayd93]

Seeing as how you are still getting some sort of impact on the primer, it seems to be an issue with your hammer spring or the firing pin itself. As others have said, check your firing pin channel for any sort of blockages; also, check the tip of your firing pin to make sure it is not deformed/mushroomed.

Is this now a recurring issue? Did you try shooting other rounds after encountering the one that would not set off? If you are using a lightweight trigger set-up, it could also be that you just encountered a harder-than-normal primer and your hammer-spring is too light to impact the firing pin hard enough.

 

[Cannonman]

I'll get my camera to load a few more shots. I've got a comparison .308 where the pin "seems" to protrude a bit more. No idea how to measure. The BCG is basically brand new. 20 rounds?

 

[No_Regerts]

Is that a homebuild? Did you install the barrel yourself? Maybe excessive headspace?

 

[Cannonman]

It is a home build. Factory ammo. It shot fine but an adjustable gas block was highly recommended

Seeing as how you are still getting some sort of impact on the primer, it seems to be an issue with your hammer spring or the firing pin itself. As others have said, check your firing pin channel for any sort of blockages; also, check the tip of your firing pin to make sure it is not deformed/mushroomed.

Is this now a recurring issue? Did you try shooting other rounds after encountering the one that would not set off? If you are using a lightweight trigger set-up, it could also be that you just encountered a harder-than-normal primer and your hammer-spring is too light to impact the firing pin hard enough.

OK, this is a two stage Gieslle trigger. About 2# on the second stage.
. It still shot as block was slowly opened to find optimal amount of gas. Now this primer problem. The lower pin is the problem. The upper is from a working .308.

 

[mhayd93]

It is a home build. Factory ammo. It shot fine but an adjustable gas block was highly recommended

OK, this is a two stage Gieslle trigger. About 2# on the second stage.
. It still shot as block was slowly opened to find optimal amount of gas. Now this primer problem. The lower pin is the problem. The upper is from a working .308.

View attachment 852715 View attachment 852716

From what I can see, there definitely appears to be less protrusion on the firing pin in the bottom bolt! If you can, put the firing pin from the "good" bolt into the "bad" one; then check and see if the protrusion is the same or changes.

 

[Cannonman]

From what I can see, there definitely appears to be less protrusion on the firing pin in the bottom bolt! If you can, put the firing pin from the "good" bolt into the "bad" one; then check and see if the protrusion is the same or changes.

Thanks! Here's another head scratcher, the BCG from the Black Rain hits a section of the new build. Or doesn't fit. See that "scratch" at the end of the black marker? That came from trying the BCG for the other .308. Can't thank you enough for trying to help!

 

[Cannonman]

View attachment 851279

I've got it in right but this is happening: I took apart a few rounds of different .308 to check primer strikes. Cleaned pin and bolt. It fired once. When I take the lower from a black rain it fires with no problem. I'm thinking hammer spring? It's a two stage Geisselle. It had worked before. It ran for about 4-5 rounds when I was adjusting the gas block. Thoughts?

 

[Cannonman]

From what I can see, there definitely appears to be less protrusion on the firing pin in the bottom bolt! If you can, put the firing pin from the "good" bolt into the "bad" one; then check and see if the protrusion is the same or changes.

Tried this. Thanks but no difference. Both pins look the same. very low use one one and the other is new. I just tried a different trigger spring. Still no. When I switch the lowers it strikes. The working trigger is a drop in. It seems that if things work with the other lower that the problem is with the lower?

 

[mhayd93]

Tried this. Thanks but no difference. Both pins look the same. very low use one one and the other is new. I just tried a different trigger spring. Still no. When I switch the lowers it strikes. The working trigger is a drop in. It seems that if things work with the other lower that the problem is with the lower?

Ok that is good to know!

That would definitely seem to point to an issue in your fire control group (hammer or trigger) then with the trouble lower! If you really wanted to confirm this, swap out the fire control group for the one from the "good" lower and try again!

 

[mhayd93]

Also I forgot to ask, what is the specific model of the Geissele trigger you are using in the lower that isn't working?

What is the model of the trigger in your "good" lower?

 

[Cannonman]

Also I forgot to ask, what is the specific model of the Geissele trigger you are using in the lower that isn't working?

What is the model of the trigger in your "good" lower?

Sorry to report that I forgot which Geissele other than a two stage, non-adjustable for around $250? The other is a drop in that was done years ago. However, I got to chat with a guy who was in a gunsmith class that way advanced from me. He sounds like you. The idea being to try the trigger. I put a different trigger spring on the Geissele with no luck. Today I'm going to replace the whole thing. Somewhere in this I hope to make it work prior to putting the drop in from the black rain. Hope that you and my old acquaintance prove that great minds think alike!

 

[SUPER X]

Steel cased ammo might be the issue it has harder primers than whats common in brass cased USA AMMO.

 

[Cannonman]

Also I forgot to ask, what is the specific model of the Geissele trigger you are using in the lower that isn't working?

What is the model of the trigger in your "good" lower?

I changed out the triggers. Or I put the drop in trigger from the black rain, aftermarket, and the darn thing still won't go bang. I'm going to pull the hand guard and check if barrel is seated. I guess? I just am at my wits end!

 

[mhayd93]

I changed out the triggers. Or I put the drop in trigger from the black rain, aftermarket, and the darn thing still won't go bang. I'm going to pull the hand guard and check if barrel is seated. I guess? I just am at my wits end!

While unfortunate, it does at least rule out any issues with the trigger or bolt carrier group! That is good!

You are on the right track regarding the next step; there must be something wrong in the upper. As someone else mentioned previously, it could be excessive head-spacing in the chamber of your barrel, causing the rounds to seat too deep when in battery. Definitely check your barrel to ensure it is seated all the way!

 

[Cannonman]

Is that a homebuild? Did you install the barrel yourself? Maybe excessive headspace?

SO This is where I'm at now. I plan on pulling the barrel. But, is it here that go, no-go gages are needed? When i've go nothing but the stripped upper and barrel, barrel nut, then what? Thanks. No idea what next?