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Firing pin retainer bent

Jus228

Joined: Jun 2002

Posts: 2233

EE: 100% (1)

VT, USA

Posted: 11/12/2025 6:27:33 PM EDT

I just built an 8.5” 5.56 pistol. Using a complete PSA upper and Anderson lower with a HBPDW brace. About 100rds thru it so far and no issues it shoots great and runs like a raped ape!

I took it apart the other night to inspect things and the firing pin retainer came out hard. When i got it out it was badly bent. Never encountered this.

Brass ejection has been 2-3 o’clock with all the m193 spec stuff I’ve shot thru it so far.

timkel

Joined: Feb 2001

Posts: 2491

EE: 100% (5)

USA

Posted: 11/12/2025 7:16:24 PM EDT

[#1]

Just replace it and get back out there.

ronemus

Joined: Jan 2001

Posts: 1079

EE: 0% (0)

WI, USA

Posted: 11/12/2025 7:55:27 PM EDT

[#2]

The heat treat on some retiners is bad, leaving them soft and easily bent - get a batch from a reputable source and you should be GTG. Mine last a long time (multiple barrels).

mtwarych

Joined: Mar 2012

Posts: 649

EE: 0% (0)

MT, USA

Posted: 11/14/2025 3:30:24 PM EDT

[#3]

I had a DPMS gasser that had the same problem. As soon as I got the over-gas problem taken care of, no more bent retaining pins.

I believe the bolt unlocking too early and the bolt opening under higher pressure causes faster, more violent recoil stroke basically slamming the firing pin backward bending the retainer.

Jus228

Joined: Jun 2002

Posts: 2234

EE: 100% (1)

VT, USA

Posted: 11/14/2025 6:25:35 PM EDT

[#4]

This thing definitely recoils more than any AR I’ve built or bought. It was even making the stock shitty charging handle un-latch and smack my nose.

RD20

Joined: Nov 2020

Posts: 831

EE: 0% (0)

OH, USA

Posted: 11/16/2025 6:53:22 PM EDT

[#5]

Have you tried upgrading the carbine buffer spring and buffer to something else like, a Sprinco Red or Blue spring and an H2 or an H3 buffer?

Jus228

Joined: Jun 2002

Posts: 2235

EE: 100% (1)

VT, USA

Posted: 11/16/2025 8:23:59 PM EDT

[#6]

I’m using a HBPDW brace so a proprietary buffer and spring. I’m looking for suitable options for a heavier buffer though for sure.

TheQuadfather

Joined: Aug 2011

Posts: 21017

EE: 100% (796)

TX, USA

Posted: 12/13/2025 2:58:42 PM EDT

[#7]

Soft pin or/and overgassed.

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Firing pin retainer bent

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Firing pin retainer bent