AR - Occasional light primer strike..

[Mity2]

as title states.
My AR have DPMS stock BCG, and occasionaly experiences light primer hit(may be one every 30 rounds or so?).

Since Im building it as my SHTF gun, I can't have that.

So where/what should I start to look?
New BCG? new hammer spring? Get a AK?

[busa dave]

I would check to see that the hammer spring is installed properly and if so then make sure firing pin channel is clean. Possibly replace the spring. Did you build this or buy as a complete rifle?

[Orion0317]

as title states.
My AR have DPMS stock BCG, and occasionaly experiences light primer hit(may be one every 30 rounds or so?).

Since Im building it as my SHTF gun, I can't have that.

So where/what should I start to look?
New BCG? new hammer spring? Get a AK?

What brand of ammunition? Wolf is infamous for causing light strikes.

Just what I would do: Dissasemble the BCG, clean it thurougly, reassemble and if it keeps happening, swap out the spring for a new one. If it still happens, (doubtful) check the buffer tube spring...I know, that's grasping at straws, but that may be it.

Get an AK is always the answer though. (I kid, I kid )

[Mity2]

I built it.
Lower is Anvilarms, LPK is DPMS.

[busa dave]

Is this the first time shooting it? The reason i ask is because i've seen alot of people install the hammer spring backwards and it causes light strikes.

[Mity2]

I guess hammer spring can be installed backwords. I'll check that.
This gun - while newly rebuilt, lower has been in service with my other AR for over a year, and I never had this issue.

Last time I was out was first time I experienced it. But after trying it several times, round never did go off. So I assumed it must have been a bad ammo.
But today, every light primer striekd ammo went off the second time.
So I know its light primer strike.

Ammo I was using was PMC bronz.

I just installed anti-walk pin, which is an over sized pin. I wonder that could be the reason?

[Orion0317]

I just installed anti-walk pin, which is an over sized pin. I wonder that could be the reason?

Sounds like a good candidate to me. If it ran fine before that, and didn't after, I'd say that's it.

I hate to sound ignorant, but what is an "anti walk" pin?

[Mity2]

OMFG! I"M EMBARRESSED TO REPORT THAT INFACT I DID HAVE MY HAMMER SPRING INSTALLED BACKWORDS!!!

Holy crap how long has it been this way!?
I remenber I took LPK apart last summer to clean out/Inspect, and appearently I put it back on backwords!
Come to think of it, I had to get the anti walk pin, because my trigger pin kept backing out on me, and I thought may be because AnvilArm lower's holes are tiny bit on large side.
No, it kept backing out, because the leg of hammer pin was not putting appropriate amount of force on the grove of the pin, because I had it on backwords!
it takes alot more pulling to cock the charging handle(like my other factory built AR - My carbine was MUCH lighter. I thought it was because shorter recoil spring!) too

I'll take it out again tomorrow and see if light primer hit is no more!

I hate to sound ignorant, but what is an "anti walk" pin?

Oversize pins(Anti-Walk pin) hold hammer and trigger in precise alignment without the free play and camming action that prevents a clean and consistent trigger letoff. Two external E clips locate pins to frame, which allows pins not to come out, unless you take it out

http://www.brownells.com/.aspx/pid=7...ANTI_WALK_PINS

[Orion0317]

Oversize pins(Anti-Walk pin) hold hammer and trigger in precise alignment without the free play and camming action that prevents a clean and consistent trigger letoff. Two external E clips locate pins to frame, which allows pins not to come out, unless you take it out

Ahh...understood. Thank you!

And hey, at least you figured it out! Good luck tomorrow.

[Kaos]

A lot of people run the backwards, and they work and never know the difference...and prefer it because you have a perceived lighter trigger pull.

You can do the 15 min trig job on a properly installed spring set for a lighter pull.

Another thing that I do is run the pins in my dremel and buff the working surfaces with 00 steel wool to polish them (with a small amount of polishing compund too). I don't get light strikes with mine in over a case or so of ammo.