9mm ar15 not firing

[captain awesome]

Hey guys i am having trouble with my PSA 9mm ar15. It has always been able to fire dispite being a jam-o-matic. Now it has quit all together. I swapped lowers with an ar15 i know works and no change. Still no bang. So i checked out the upper bolt carrier group. I compared the back end of the firing pin to another AR (6.8 ruger sr556) and noticed that their is a difference in how far they protrude out the part where the hammer hits. The 9mm even when the back end is past where the hammer stops still does not push it far enough to come in contact with the primer. The 6.8's does. The puzzling thing is the firing pin on the 9mm does not appear to be broken or damaged. Is this normal?

I measured the total length of the firing pin on the 9mm from front to back with a set of dial calipers and its 2.648 inches long. Is anyone who has one of these rifle able to measure theirs? I would call PSA and ask them for advise but i am qat work while their CS dept. Is open and am unable to spend any length of time on the phone at work. Cleaned and lubed the rifle thoroughly and re lubricated it and tested the round on a different 9mm rifle just to make sure its not the ammo and the rounds function fine. But in the psa there is not even a mark on the primer. The bolt apears to be all the way forward. Anyway thanks in advance for any help or advice on what to do next. I hope i just need a new firing pin and can order one real quick

 

[243winxb]

Does the 9mm have an inertia firing pin? They are shorter and keep going forward till they make contact with the primer. To much oil or dirt in the firing pin channel may slow it.

[/URL][/IMG] Wait till another PSA 9mm owner comments.

 

[langss]

I'm using a CMMG bolt and it has a spring around the Firing Pin that keeps it retracted. Possibly as posted above you have something preventing the Firing Pin from moving forward when struck.

 

[captain awesome]

So i did some digging and more expirimenting. I guess my psa has a particularly tight chamber. They are indeed inertia firing pins. I am amazed they manage to keep enough inertia to actually set of a primer. Anyway i cleaned it all out and slicked it up and still wasnt getting any rounds firing (i have a steel bullet box that i can shoot up to 30-06 into in my reloading room, makes solving problems like this SO much easier) so i did some more looking and decided to got get an undersized sizing die and a lee carbide factory crimp die. Called around and one of the big box stores happened to have them. It took every last bit of adjustment on the FCD but i got it working. I cant beleave it worked, i could swear the action was fully closed before. I also dont get why they were working at first and then quit working even after i cleaned it. But it fired a whole mag with only one jam (failure to eject a spent casing) which is a first for that rifle, the best i have done is 3 failures in 20 rounds before. Anyway as you have deduced they are reloads, but have always worked in several other 9mm's of various mfgs. Guess i should get some go/no go gages. Hope this helps someone else in the future. Thanks guys

 

[joem1945]

when I set up my reloading dies I always use a max length cartridge gauge. If the round drops into the gauge it usually will fire in any one of my firearms.

 

[HJ857]

My CMMG upper and bolt came with a pretty crappy firing pin. It wore out and failed to fire within a thousand or two rounds. I replaced it with a Colt pin, so don't rule out the firing pin shortening due to wear.

My Colt pin measures 2.648" so same as yours.

 

[Dain Bramage]

...dispite being a jam-o-matic...

My RAR-9 (Rock River Arms) upper was the same way. I thought it was jamming when dirty, so I cleaned the crap out of it all the time. Then, I thought it needed breaking in, so I worked the bolt. Then, I fiddled endlessly with the mag block height.

My daughter loves that rifle, and I used it to train beginners, so it was embarrassing to get heinous jams, deep in the receiver, making even separating the halves difficult.

Then, I read on the internet that the problem might be with my magazines. I did some checking out, and realized that my 10-round mags were the ones jamming, unfortunately the ones I most often used with beginners. My 32-rounders never jammed. So, I threw out my 10-rounders and didn't look back.

 

[Arizona_Mike]

My CMMG upper and bolt came with a pretty crappy firing pin. It wore out and failed to fire within a thousand or two rounds. I replaced it with a Colt pin, so don't rule out the firing pin shortening due to wear.

My Colt pin measures 2.648" so same as yours.

Ditto. My CMMG firing pin snapped in two after only a few dozen rounds. Replaced with a Colt 9mm pin and no troubles since.

Mike

 

[bfoosh006]

I have to ask... which PSA upper ?

Is it the newer Hybrid one ?

Mine works 100% straight out of the box.... ( spooky huh ? Lol )

What spring and buffer, what mags, what ammo... reloads or factory, ramped BCG or not, what hammer / trigger ?

 

[captain awesome]

Its the dedicated 9mm upper, not sure what the hybrid one is... But i bought it roughly 6 months ago. Mags are the 32 round ASC mags. Ammo is all reloads, i am going to buy a box of factory and see if i get any jams. The buffer and spring are the stock ones that came with the lower i bought (purchased the upper and lower separately, both PSA) lower is The PA-15 Multi .and i swapped the trigger out with a Geissele SSA. I dont know if the BCG is ramped or not. I have never been quite clear on how to tell. I know it makes a difference on what hammer you should use but beyond that i dont know much.

 

[bfoosh006]

The Hybrid BCG can be used in a "Glock" mag lower or the "Colt" type lower.

A ramped BCG looks like this on the underside...the ramped is longer to allow a "smoother, less stressful on the firing pins " hammer reset.



As for the trigger.... 9MM's are very fussy about triggers... my Hybrid cannot use "shortened hammers" like the Geissle triggers have.

Mine has to have a "conventional" hammer... NOTE: my hybrid BCG only... It wouldn't "reset" correctly with the Geissele S3G, the hammer would follow the carrier !

You MIGHT need a hammer like the pictured 9MM hammer. ( Don't run out and order one yet ! )




Can you post a photo of the underside of your BCG ?


Also... I have found ASC mags to be "rough" feeding... mine were rough ( on the inside) in the backside channel... a 1gal paint stick fed down that channel in a disassembled mag will let you feel any grittiness. Mine were easy to sand away any roughness by wrapping 300 / 400 grit sandpaper around the 1gal paint stick and polishing the gritty parts away.


This linked thread is well worth reading...
https://www.ar15.com/archive/topic.html?b=3&f=15&t=507087

 

[bfoosh006]

Let us know how it fires with factory ammo...

If it is still fussy....I would try a conventional trigger group in your rifle...

The pictured LPK from PSA shows a routine hammer.

The ALG ACT works in mine.

 

[captain awesome]

Here you go

[/URL][/IMG]

 

[captain awesome]

Yes i have noticed the mags are very rough. Its so bad that i cant even load a whole mag. I still have the original trigger i can always drop back in. Here is a pic of the one i took out of the PSA lower and one i took out of my Ruger 6.8 the one on the top is the PSA

[/URL][/IMG]

 

[bfoosh006]

I can't quite tell if that BCG is ramped all the way... I will compare it to internet photos and my PSA Hybrid tonight.

I do believe that is a ramped bolt... it may just be a shorter ramp then mine.

With a little fancy handling... you can see the interface between the BCG and hammer by removing the BCG from the upper and holding it firmly while you function the "action" ... sliding the loose BCG into the empty buffer tube and see how your current SSA hammer is interacting with the firing pin. I can't help but wonder if "somehow" the Hammer is binding along the BCG.

Also.... fix those mags... ( Try the 1 gal stir stick trick )....if they do not feed correctly then the rifle will have a hell of a time feeding properly. Brownells sells their own brand Colt Style 9MM mags that are fantastic. ( My first choice, as long as they are on sale. ( The 3 pack was just 80 bucks a little time ago )

And PSA sells rebranded Metalform ones for a good price...BUT you have to degrease what ever the sticky packing goo is from inside the mags, and on the follower for really smooth function.

And buy the Maglula "Colt SMG" loader... even with very smooth functioning mags, loading the mags can be a bit of a PITA.

http://www.midwayusa.com/product/855269/maglula-magazine-loader-and-unloader-colt-smg-ar-15-9mm-luger


I would try the PSA hammer though. When you do install the PSA hammer... BE SURE to dryfire the lower and manipulate it by hand to make sure everything about the trigger operation works correctly prior to live fire.

As I mentioned my Geiessele S3G would not operate ( specifically, the safety reset did not function ) correctly.

Also.. what kind of rifle stock are you using ?

 

[eldon519]

When I was researching which mags to use, Metalform was often said to be the best. I bought a bunch of them, and they work great.

Also try bump-loading them. Makes it really easy.

 

[bfoosh006]

eldon519... try the Brownells... I like them much more then the Metalform.

Better coating on them, more corrosion resistant... same solidly build though.

And great thinking on the bump loading, I haven't tried that.

 

[HJ857]

I agree with the swapping the trigger group. The RRA match trigger will not work in a 9mm either, for exactly the same reason as previously stated.

Also agree with the ALG ACT trigger. It's really nice in my AR-9.

I tried the ASC mags (AR Stoner at Midway). They're great and an awesome price too. I think I have 12 of them now and they all function perfectly. Mine is Colt pattern.

 

[langss]

In my limited experience with the 9mm AR that I put together, I had a problem in the beginning before I ever shot the thing, with the bolt hanging up on the magazines. What I found out was that the "Coating" that ASC puts on the magazines is just thick enough to hang the bolt up. Now the magazines I got are Stainless Steel so no real worries with rusting, so I carefully removed the coating that was interfering with the bolts travel and for the most part the problem went away. I did have to experiment with exactly where I had to remove the coating on each magazine and it took a few hangups when actually firing the gun to get them all to work, but I have well over a 1000 down the pipe now and no further problems. I hope this help.

 

[eldon519]

Unless something has changed, the Brownells mags are made by Metalform. PSA and Colt as well.

 

[bfoosh006]

I should have been more specific on the Brownells mags.... the coating is what I am really impressed with , it makes the already great Metalforms even better.

Matte black Xylan coated magazine body
• Xylan coating drastically reduces friction and provides excellent corrosion resistance