Issue with PSA AR-9

[Velzey]

The back of the firing pin...Its been modded. Sure its making good contact with the hammer? That last picture you posted looks like I see the rear of the pin, and that should be enough. But, does the hammer come forward enough to make full contact.

And any standard AR hammer spring has enough poop to pop a small pistol primer!

 

[B5Ben]

Is the PSA carrier weighted like this? The YHM is filled with a block with an arc cut out for hammer rotation.

 

[IronMonster]

Yep, real similar to that.

 

[Page.k]

Hi,
I think you should check the location of the rear of the barrel to one of the uppers that your buddy has on order. I think the barrel did not end up back in the same location when you changed out the hand guards. If the barrel is a little too far back or forward it will give you the primer strikes you're talking about. The barrel location affects the location of the rear of the firing pin and can lead to the hammer not getting a clean hit on the pin.
Also so if the buffer mass is to much or little it can move the bolt out of battery and the force of the hammer is moving it back to the barrel. So check the brass for a puffed out rang around the base of the round. To keep people same from a good primer strike with the bolt out of battery the bolt will need to be in the correct "window" to fire a round.

Please never use a older style 9mm AR bolt in a newer AR upper.

 

[Medic!]

What are you doing?

Why are you grinding the bolt carrier if the gun cycles ammo well?
The first thing you should have done [as with any new gun] is try several types of ammo. If the gun jams then try a new mag. Then fix the gun!


That said I do think you need a heavy duty hammer spring to counter the firing pin spring.
They must have done that to counter slam fire. Since not all 9mm ammo has a hardened primer.

 

[IronMonster]

What are you doing?

Why are you grinding the bolt carrier if the gun cycles ammo well?
The first thing you should have done [as with any new gun] is try several types of ammo. If the gun jams then try a new mag. Then fix the gun!

I have had S&B 9mm ammo with primers so hard they would not fire in anything but my UZI's.

That said I do think you need a heavy duty hammer spring to counter the firing pin spring.
They must have done that to counter slam fire. Since not all 9mm ammo has a hardened primer.

The ramp ground into the bolt has nothing to do with feeding ammo nor my current issues. Usually in a 9MM AR you either use a special 9MM hammer and a non ramped bolt or a standard hammer and a ramped bolt. The kit came with a standard hammer and a non ramped bolt and since I have a machine shop it was easier for me to machine the ramp in the bolt than it was to buy a special hammer. The ramp takes some of the stress off the hammer pin and reduces friction during the hammer reset, it has nothing to do with feeding ammo.

Hi,
I think you should check the location of the rear of the barrel to one of the uppers that your buddy has on order. I think the barrel did not end up back in the same location when you changed out the hand guards. If the barrel is a little too far back or forward it will give you the primer strikes you're talking about. The barrel location affects the location of the rear of the firing pin and can lead to the hammer not getting a clean hit on the pin.
Also so if the buffer mass is to much or little it can move the bolt out of battery and the force of the hammer is moving it back to the barrel. So check the brass for a puffed out rang around the base of the round. To keep people same from a good primer strike with the bolt out of battery the bolt will need to be in the correct "window" to fire a round.

Please never use a older style 9mm AR bolt in a newer AR upper.

I am not sure I follow. The barrel seats in the upper, you could take it out and put it back and there is nothing that could change. I understand that if you spaced the barrel out away from the bolt it would change the headspace, however the barrel seats into the receiver in such a way that it should not be effected by removal and installation.

I have not got my extra power hammer springs yet but I figure they will solve my issues.

 

[Medic!]

Good morning Ironmonster.

I understand the carrier mod. It's an improvement no doubt.
And you did say the ammo ran in other guns. But different ammo is always a good diagnostic tool. That's all I meant. Ammo, magazine, then modify is just a general rule.

I think the new hammer spring will do it.

You could always remove the fire pin spring. Load five rounds. And try that. Just be ready for full auto!
Just another diagnostic tool.

 

[Page.k]

Let us know what you find out. Next time you take it out can you share some photos of the unfired round and fired brass?

 

[IronMonster]

Absolutely, I got my extra power hammer spring today so hopefully soon I'll get a chance to go tested out

 

[jbett98]

How hard would it be to build a bullet trap that would work indoors and also be somewhat sound deadening.
Your shop must make a bunch of noise all day long, would anyone notice a couple of rounds being test fired.

 

[IronMonster]

How hard would it be to build a bullet trap that would work indoors and also be somewhat sound deadening.
Your shop must make a bunch of noise all day long, would anyone notice a couple of rounds being test fired.

I have actually seriously considered doing just that. Its in an industrial area and noise would not be a problem, If I was overly worried about the noise I could just start up my big forging hammer and it would muffle it well.

 

[IronMonster]

I got the extra power hammer spring today, while I was messing with it I realized the mag catch was just barely poking through the adapter and mags where not as secure as I would like (one dropped out as I was packing it to the table). I built up the catch area by TIG'ing on some inconel and then a little shape and polish. Works much better now

 

[spectra]

Someone needs to go see those Asian ladies for a manicure

Does suck working with your hands.....my wife yells at me all the time

 

[IronMonster]

I dunno what your talkin about, I just got a manicure.

 

[mcathcart]

Ive had the same mag catch issue, but I was able to just swap the part out with another. Problem solved. Not all lpk's are equal. Good luck with the new hammer spring. I think thats your fix.

 

[SOrez]

I had a problem with the mags going in too far. I cut a bike inner tube at the angle of magwell put it on the mags and that solved my problem

 

[jbett98]

Can you regulate the mag catch depth by how far you screw in the mag catch release bar?

 

[IronMonster]

Its the added thickness of the mag well adapter that is the issue.

It seems like you can affect the depth by how far you screw on the mag button. But in this case as much as you could get was not enough.

 

[Page.k]

Any updates?

 

[IronMonster]

I have got the thing back together with the XP spring and test fired two rounds in my clearing trap. That seemed to solve the issue. I am hoping to get to take it to the range and see how it runs for real.

On a side note I helped build two more of the same kits for a friend. Both of his ran great right out of the box.