Light Primer Strikes - on all 5 rifles ** UPDATE, problem not fixed

My dad asked for my advice in which AR to get. I reccomended PSA (although I've never owned PSA).
He bought 5 rifles: stripped lowers w/ parts kits and complete uppers (various configs).
I talked him through assembly of the rifles over the phone. He tried them out yesterday....

All 5 rifles are malfunctioning with light primer strikes. He is using IMI855 and Wolf .223. Same result with both ammo.
I am thousands of miles away, so I can't personally examine the rifles.

Is this an issue that anyone here has encountered before? Any ideas what is causing it?
Is it possible that the trigger group was assembled incorrectly?
Is there some kind of packing grease that needs to be cleaned out of the bolt?

The rifle is feeding and ejecting correctly (when it fires). Brass ejects to the 4 o'clock.
The ammo that failed to fire the first time will usually fire on a second try.

ETA: I will talk to him tomorrow to probe more into the problem. I just wanted to see if anyone has had a similar experience and can solve it right off the bat.
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Update: The hammer springs were installed correctly. Now I'm back to square 1. Any other ideas?

those are the FIRST thing to check.... plenty of resources here to stare and compare....

Is it easy to inadvertently assemble a trigger group incorrectly such that it still kinda works?

Sounds like the hammer springs aren't installed correctly.

All built by the same guy.+ all have the same problem = all assembled incorrectly they same way.

Hammer springs would be the first thing I would look at.

Yes. Check that the hammer and trigger springs are installed correctly.

Hammer spring is on upside down, or backwards...depends on how you look at it.......guarantee'd

Trigger spring only goes on one way, hammer spring can be put on 2 different ways. The wrong way will yield light primer strikes, the correct way will not.

99.9999% sure that his lowers all look like this



that is incorrect hammer spring orientation. lowers should look like this



spring ears should be coming off the bottom, not top

left is the wrong way, right is the correct way

Excelent pics.
Thanks for all the replys. We'll get it fixed.

Update in OP. The rifles were assembled correctly.

i'm not buying it, i require a picture of one of the assembled lowers

5 different complete uppers, all malfunctioning the same way on 5 different lowers with two different ammo manufacturers, all assembled by the same guy = incorrect lower assembly

ETA: i've never seen it done this way and you'd have trigger pins wandering around like they were homeless but i suppose he could have the springs installed correctly on the hammers but not have the spring ears on top of the trigger pins but instead under them, pushing only against the bottom of the lower itself

just a passing thought, note that the spring ears from the hammer spring sit on top of the trigger pin in those grooves both for proper spring tension and to keep the trigger pin in place

Strange... all eight of my PSA AR15s cycle and fire as they were designed to do without a hitch. As do about a thousand other AR rifles built from their parts. Hmmmm.....

When i assembled and shot mine for first time i.had light primer strikes after about 60 rounds. I oiled up the bcg more and then it shot fine.

Yup. Did this with my first build. Luckily I had another rifle and was able to hearandfeel the difference when I would pull the triggers.

Pull out the firing pin and hose down the bolt / carrier group / etc with CLP, report back.

Are you using special springs? I had light primer strikes using JP Enterprises springs.

I have bought 3 LPK's from PSA and found their hammer springs to be on the light side. I changed them all out to Armalite springs I bought from DSG and the light primer strike problems went away.

I love their parts kits. Getting ready to order another today for my Calico Jack I just ordered. But I have an Armalite spring already in my parts box for it.

Edit, just ordered parts kit #4 and 2 boxes of 308 FGMM. Just couldn't help myself on the ammo. 2 boxes for the price of one at my local shop.

Dude, lay off the PSA kool aid. He isn't blaming PSA. He just needs help.

I'm no expert but if it's not the hammer spring(usually the case) then as others have said he should take apart the bolt assembly and clean and lube everything nicely. I've never had any issues with mine but I'm pretty particular about keeping it lubed up.

Good luck,

Paul

Well, this is the PSA section you know....so the majority of us here drink the PSA kool aid on a regular basis. I like to mix my orange and grape PSA kool aid and make SHTF Brown PSA kool aid.

We have all been giving OP help, if non of this works, I would tell him to take it to someone who has built these before and have them look at it. Very hard for us to help without pictures to know what is really going on.

I've never had a problem with my PSA parts that I installed in my lower, or my g/f's, or my roomates. I even run JP yellow springs in mine and still don't have light strikes. So that leads me to believe something is not installed correctly. Or something could be out of spec....we can't tell without pictures.

triple check the orientation of the hammer springs, and that they are above the pivot pin for the trigger. Also check if there is grease in the Bolt/BCG, that could slow down the pin alot and cause issues.

They were stripped lowers, not complete. OP's dad assembled them.

Dad just ordered new hammer springs and degreased/relubed the bolts.

Sorry this is dragging out so long. He doesn't have a lot of time for toys right now.

I'll post updates if he ever makes it out to the range again.

Did you see pictures of the lowers to verify the hammer spring orientation, or just explain it to him how it should be? If the latter, there may have been mis-communication and the hammer spring is still the problem. See if you can talk him into getting you a few pictures to post (if you haven't gotten them already).

If one or maybe two were acting up, I could see there being an issue in the BCG. Since it is all five, I think it is more likely to be something assembled incorrectly. Something may have changed, but I assembled a PSA rifle for a friend a few months ago and his BCG was just lightly oiled/greased, no where near to the point it would start causing issues.

Here's another thing to check- the spring may be installed correctly but the arms may be below the trigger pin. They should be resting on top of it (which also helps hold it in place). I'm not sure how folks do it that way, but I've seen it done once. There is or was a mod where folk were shortening one leg of the hammer spring to lighten the trigger pull but I've never actually seen anyone do it.

PSA test fires their uppers (several rounds each) so I have a hard time believing the problem is in the uppers. When the lowers were assembled, the builder should have test fit the pins in the hammer and trigger and would have noted any friction at that time i.e. they were out of spec or something in one of the holes.

Let someone experianced with AR's look at them.

A fresh set of eyes might uncover something simple that you are overlooking.

I know this must be getting frustrating for you and your father, but you could do yourself a massive favor by simply taking, or having your Dad take 2 or 3 pics inside the lower and then posting them in this thread. If you need help posting the pics, any of us would be more than happy to help I'm sure.

Make sure the disconnector spring in installed with the large end down inside the trigger not at the top.

This will only cause random doubling, won't affect the hammer swing strength. Trust me, I know

science time. so to determine if itis the upper or lower, take KNOWN good rifle, take it apart, test with each unknown upper, test each lower with known good upper. find differances, profit.

It can cause both.

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