Jump to content
Brian Enos's Forums... Maku mozo!

How often do you replace your firing pin in an AR-9?

Recommended Posts

I shot in my local club USPSA match last night and had a few "failures to fire" during the three stages we shot.  When I got home I  pulled the bolt and found that the firing pin was broken right at the spot where the firing pin is machined down to a smaller diameter.


Two questions-is this where it normally breaks, and more importantly, how many rounds do you put down the tube before you change it?  Unfortunately I don't remember how many rounds I have through the rifle but I'm assuming it's around  1500. Also, how many rounds do most of you usually get out of a pin before it breaks? Wondering if I just had a bad pin-the break is super smooth and right at the point that the pin is machined down to its final diameter.


Link to post

Come to think of it, the reason that the two opposing pieces of firing pin look so smooth and polished is because it's been broken for a while and the two pieces slamming together have peened each other smooth???????

Edited by copterdrvr
Link to post

Haven't shot mine enough to break a firing pin, yet.


I would like to tell you that not all 9MM AR firing pins work in all 9MM AR bolts.


After hearing of short life for the firing pins I bought some spares.  Wilson Combat firing pins.  My nephew figured he'd just go ahead and replace the firing pin in his fairly new PSA 9MM bolt prior to a range trip.  Got to the range and loaded it up and not a single bang in spite of multiple attempts to fire.  Brought it over to the house later and we noticed the small diameter section that protrudes through the bolt face was longer on the PSA firing pins vs the Wilson Combat firing pins.  Same on my PSA bolt/firing pin.  However, the Wilson Combat firing pins worked great in another 9MM bolt installed in my carbine (Faxon bolt).


So, not saying any brand is bad, but differences in the bolts can affect what brand of firing pin will work.  Compare the firing pins visually at the time of replacement/before you head to the range.


Good luck.

Link to post

Thanks for the reply.  I have another AR9 bolt that I tried but it has an AR style extractor which cuts a slot into the side of the bolt. I'm a Lefty and I found that when I used this bolt I had ejecta from the action striking my face. I assume it was following the cut in the bolt which is .17 inch deep. ANYWAY, I pulled the firing pin out of it to try in the original bolt and noticed it had a slightly different location of the taper where it goes from its thickest to thinnest transition. I also looked at the tips of both and they looked the same.


Just to make sure, I used the short arm of an Allen wrench and pushed the firing pin as far forward as it would go in the bolt and the firing pin protrusion looked good.  I did order a couple spares from the bolt manufacturer and got an email from them that they shipped so hopefully I will have the "factory" pins before this coming Wednesday!


I'd still like to hear from AR9 shooters about their typical firing pin life cycles or how often they just arbitrarily change them.


Thanks for the replies!

Link to post

Have broken two pins . Both broke the very tip off. They had over 30k when this happend. Found that if I change the firing pin spring they last a very long time.

Current pin has over 50k and still good to go.   Have seen other peoples pins break like yours.    PSA's latest pin may be the best out thear to pevent brakeage as you

have experanced.   Other wise the Willson Combat.       FYI before you ask the pin with over 50k is the latest PSA pin.

Link to post

I broke a blue steel OEM pin at about 400 rounds... replaced it with a Colt pin, and rounded the strike end so the hammer will hit closer to the center line of the pin... first in a blow back and now RDB carbine... estimate 7000 rounds

Link to post

You can order directly from iron city rifle works too. They have been very helpful. I use there pins. They make ones with different profiles at the tip. I have probably 10,000 rounds or more on mine.


Link to post

I carry two or three CMMG firing pins and springs.  I've bent and broken more springs than I have firing pins.  With that said, I change them when they break or when I clean them and I notice the actual firing pin mushrooming.  I change both the spring and the pin at the same time.  Also, the CMMG firing pins work well with both the Taccom and PSA bots.

Link to post

Thanks for the info!


I never heard of Iron City-they actually had titanium pins in stock and I ordered two.

Curious about how the springs can get bent or broken without the pin breaking-is that because of the finish/contour of the inside of the bolt?


Also, when I first put the rifle together I did a BUNCH of dry firing in general AND with swapping triggers-could that have an "impact" (so to speak!) on breaking the firing pin with a relatively low round count?

Edited by copterdrvr
Link to post

I have broken 2, 1 was the original NFA Bolt FP, the second was a Wilson. Both were within a couple of thousand rounds. Went to Taccom FPs & springs in both our PCC's and have over 10K on both with no breakage. Do keep a couple of spares just in case. I inspect and clean them every so often.



Link to post

I have at least 20K rounds on a Taccom firing pin in my  Taccom ULW 5.25" barreled PCC .. using a Hyper Fire trigger competition trigger ... i do have spares in my range bag..

Link to post

I ordered two titanium pins from Iron City it seems like yesterday (not really) and they arrived TODAY! They are really finely machined and I immediately installed one of them in my bolt. They are definitely well machined pins with no sharp edges on the shaft anywhere and very finely finished. They make the other pins I received from another manufacturer look like crap.....

Link to post

When they break. I carry an extra pin and bolt just in case. 10s of thousands of rounds through 3 guns and only one broke. It was an ATI. Which they sent me a new bolt to replace the broken pin.


Link to post

re: breaking more than 5.56 pin... my perception was the reason I suggest rounding the strike end of the pin... OEM pin and Colt OEM is squared off, and I noticed that the edge of my factory OEM was slightly peened when it broke, as the hammer struck it off center... the 5.56 pin is rounded, so why not do the same for the 9mm pin with the same hammer strike?

Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...