Light Primer Strikes on AR?

[Vanillagerrilla]

I am getting some light primer strikes on my AR.
Its not very consistent either, sometimes it will be on the first round in a magazine, some times its the fifth round, sometimes its every round....
Each primer has had a dent in it, trigger goes CLICK, but no BANG.
Its a MIL spec BCG on a 16" STS upper, AERO lower with MIL spec trigger .
Ive read that it could be
Buffer not heavy enough
Buffer Spring worn out
Hammer spring in backwards
too light a hammer spring
dirty gun
....
Any body have a similar issue or solutions?
Thanks

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[oli700]

you have pulled he firing pin and looked for obstruction in the bolt body ?

can you get a couple pics of the prime cups ?

 

[Vanillagerrilla]

Unfortunately no. I put it back in its cage when I got home from the range and had to head out.
Im going to strip it down tonight, look at the chamber and lugs, then see what might be holding up

 

[oli700]

the only time I had that was an obstruction in the bolt body.......it was a tiny piece of a primer cup that got punched back through the firing pin hole

also might make sure the FP is in spec, sometimes there is a tolerance stack between the bolt body and the FP demission.....they can both be on the extreme ends of acceptable tolerance but put together the FP might not protrude the same each reset and discharge if there is even a touch of crap in the bolt body .....

 

[Certaindeaf]

So the primers show that they are all getting hit to the same depth and some are not going off? What kind of ammunition are you using.. does this ammo work in other guns?

 

[oli700]

So the primers show that they are all getting hit to the same depth and some are not going off? What kind of ammunition are you using.. does this ammo work in other guns?

that's why we need some pics

 

[Vanillagerrilla]

I bought a new box of 223 federal, so I dont think its the ammo.
And some did in fact fire, so Im leaning towards dirty gun/ crud of some sort.
I will check out the FP depth. I have some calipers .
Thanks for the suggestions!

 

[oli700]

??

 

[Vanillagerrilla]

Well , it was filthy inside the chamber at the lugs.
The carbon build up was pretty bad all over the BCG , and there seemed to be some sludge building up at the FP stop.
I cleaned it pretty good and oiled it up. We shall see...

 

[Vanillagerrilla]

One other thing I noticed, I couldve swore I saw a chunk of brass in the lug/chamber area. Just a small bit , maybe from a case rim...
I have been using Mobil 1 5W-20 for lube for a couple years in this rifle, it seems to be losing its protective qualities as I saw by the sludge build up.
Whats a decent lube anymore?

 

[oli700]

honestly I just use Breakfree CLP on the BCG rails, little on the gas rings , little on the FP. some moly grease on the trigger sear ......that's it for my AR's

I have tried Frog lube, don't care for it

If I change its going to be Slip 2000
https://www.slip2000.com/blog/s-w-a-t-magazine-filthy-14/

 

[Velzey]

Take a picture of the hammer in the forward position and post it up for me! Just straight down looking into the trigger group..

 

[Vanillagerrilla]

 

[Vanillagerrilla]

Those were before I scrubbed it out

 

[mike1281]

I was having a similiar issue on a build I did a couple years ago. Except it was only on ammo with berdan primers. Like tula stuff. I replaced the hammer spring with a Wolff spring. That solved the problem. Best of luck getting your issue resolved.

 

[Certaindeaf]

Those were before I scrubbed it out

Do you have a chamber brush?

 

[308]

Whats a decent lube anymore?

http://www.militec1.com/index.html

 

[Vanillagerrilla]

Cool thanks guys.
I needed to get some one something for a stocking stuffer
Anyway ...

 

[Greenbug]

Almost looks like a crack is forming in the area above your barrel extension, or is it just that dirty????

 

[Vanillagerrilla]

It's that filthy . Once I cleaned the crud out , it was pretty clean. I didn't spray it down with break cleaner yet , but I re oiled everything and put it away.
I'm gonna do a more detailed break down and clean this weekend