P938 random malfunction - SIG Talk
SIG Talk Gun Forum

P938 random malfunction

This is a discussion on P938 random malfunction within the P238, P938 Pistol forums, part of the SIG Sauer Pistols category; Hi all: I have a P938SAS that is my EDC. I try to put several mags of 124gr plated RN ammo through it at each ...


Go Back   SIG Talk > SIG Sauer Forum > SIG Sauer Pistols > P238, P938 Pistol


P238, P938 Pistol All variations P238, P938

Like Tree11Likes
Reply
 
LinkBack Thread Tools Display Modes
Old 08-28-2016, 05:58 PM   #1
Member
 
drband's Avatar
 
Join Date: Sep 2015
Location: GA
Posts: 96
P938 random malfunction

Hi all: I have a P938SAS that is my EDC. I try to put several mags of 124gr plated RN ammo through it at each range trip

My carry mag is the flush fit 6-rounder.

I use a 7rd extended mag for practice with the plated RN ammo.

The malfunction is on the 5th or 6th round, the pistol chambers the rd, but the hammer is not cocked. If I cock the hammer it fires and cycles, loading the next rd just fine. It is random in occurrence and is bothersome.

I tried cleaning the 7rd mag and using a dry lube on the spring/follower. No change.

Does this sound like an ammo problem, a mag issue, or a mechanical problem with the firearm?

Any suggestions would be helpful.

Other info: my 6-rd carry mag stays loaded with 124gr gold dots. Last time I checked it--no malfunctions.

Anybody have problems with the 7-rd mags?

Thanks.
drband is offline  
Register

Welcome to the SIG Talk Forum dedicated to SIG Sauer Pistols and SIG Sauer Rifles.

We welcome everyone and the community is free to join so register today and become part of the SIG Talk Forum!

Old 08-29-2016, 02:09 AM   #2
Senior Member
 
Join Date: Mar 2015
Location: Charlotte
Posts: 114
If the round is chambered but the hammer isn't cocked then I'll bet you have the old style MSH and it's time to send it to Sig for the upgrade. What is your date of manufacture?
Poetical1 likes this.
Topgun1953 is offline  
Old 08-29-2016, 02:25 AM   #3
Supporting Member
Supporting Member
 
Sudsc61's Avatar
 
Join Date: Jan 2013
Location: Palm coast Fla.
Posts: 1,044
I use the 7 rnd mags all the time at range and if I carry (very rare) I use the 6 rnd flush mag. I've never had a issue with either. And I run 124 or 115 through it. If it only happens with the 7 rnd mag I would assume that's the problem. Just for kicks I would try to change up ammo to see what happens. For the range I use cheap Wallmart ammo.
Sudsc61 is offline  
 
Old 08-29-2016, 03:20 AM   #4
Member
 
drband's Avatar
 
Join Date: Sep 2015
Location: GA
Posts: 96
Quote:
Originally Posted by Topgun1953 View Post
If the round is chambered but the hammer isn't cocked then I'll bet you have the old style MSH and it's time to send it to Sig for the upgrade. What is your date of manufacture?


I have the new MSH. But I will disassemble and take a look anyway.
drband is offline  
Old 08-29-2016, 03:22 AM   #5
Member
 
drband's Avatar
 
Join Date: Sep 2015
Location: GA
Posts: 96
Quote:
Originally Posted by Sudsc61 View Post
I use the 7 rnd mags all the time at range and if I carry (very rare) I use the 6 rnd flush mag. I've never had a issue with either. And I run 124 or 115 through it. If it only happens with the 7 rnd mag I would assume that's the problem. Just for kicks I would try to change up ammo to see what happens. For the range I use cheap Wallmart ammo.


Will try different ammo this week.
As suggested, I will also take a look at my MSH, though I don't think it's a possible problem because I have the new version.
drband is offline  
Old 08-29-2016, 04:25 AM   #6
Senior Member
 
ThnkFrst's Avatar
 
Join Date: Mar 2012
Location: SEMI
Posts: 8,088
I doubt that the problem is ammo related. The hammer should be rotated back by the slide far enough for the sear to engage the hammer SA notch within about the first 3/4" of travel (recoil). That's well before the round is positioned to be chamber (which yours does). That would seem to rule out weak/underpowered ammo or riding the slide.

I also doubt that it's a mag issue either as you state the round chambers properly.

My best guess would be a problem with the sear mechanism; either the sear, sear pivot pin, hammer (SA notch) and/or the sear spring.

Did you install the new MSH/sear spring yourself? What kind of grips are you running? Any mods to this pistol?
Edit: How often does this happen? How long has it been happening?
Topgun1953 likes this.

Last edited by ThnkFrst; 08-29-2016 at 04:32 AM. Reason: Added a question.
ThnkFrst is online now  
Old 08-29-2016, 05:11 AM   #7
Member
 
Join Date: Jun 2016
Location: Northern Virginia
Posts: 96
+1 on ThnkFrst's suggestions.

On both of the P938s I've owned, the sear pin was pretty loose. On the first one, it didn't take much to get it wander over to one side or the other. At one point it managed to slide up over the Hogue rubber grips on the right side, putting the ejector off kilter.
kai0n7 is offline  
Old 08-29-2016, 09:04 AM   #8
Member
 
drband's Avatar
 
Join Date: Sep 2015
Location: GA
Posts: 96
I will check the sear pin.
It's a stock P938SAS with stock rosewood grips.
The upgraded MSH came installed in the gun.

Rt. grip has never been off the gun. Left was off yesterday when I checked/oiled the disconnector (just a drop).

I never thought of checking the sear pin before because yesterday was the first time I had removed the grips.

The pistol has 500-600 rds through it. This issue showed up a few weeks ago during range time and may have been present earlier. I typically only loaded 5 rds in the 7-rd mag until recently. 5 at a time slows me down and makes me take my time and analyze what I'm doing so I don't waste ammo.

I don't remember removing the MSH before, but I've been shooting the 938 at the range for well over a year--

If the sear pin is in place, should I remove & reinstall the MSH and sear spring? Just trying to eliminate wrong steps.
drband is offline  
Old 08-29-2016, 09:23 AM   #9
Member
 
Poetical1's Avatar
 
Join Date: Aug 2014
Location: journey1
Posts: 43
Quote:
Originally Posted by Topgun1953 View Post
If the round is chambered but the hammer isn't cocked then I'll bet you have the old style MSH and it's time to send it to Sig for the upgrade. What is your date of manufacture?
I had the OP's same issue.
I sent mine to Sig, got it back in just under 2 weeks. Problem solved.

Sent from my SM-G920V using Tapatalk
Poetical1 is offline  
Old 08-29-2016, 09:29 AM   #10
Member
 
Join Date: Jun 2016
Location: Northern Virginia
Posts: 96
Quote:
Originally Posted by Poetical1 View Post
I had the OP's same issue.
I sent mine to Sig, got it back in just under 2 weeks. Problem solved.

Sent from my SM-G920V using Tapatalk
Did they give you any information on what they did to fix it?
kai0n7 is offline  
Old 08-29-2016, 09:32 AM   #11
Senior Member
 
ThnkFrst's Avatar
 
Join Date: Mar 2012
Location: SEMI
Posts: 8,088
Do you know the build date (should be on the sticker on the case)?
ThnkFrst is online now  
Old 08-29-2016, 09:47 AM   #12
Member
 
Poetical1's Avatar
 
Join Date: Aug 2014
Location: journey1
Posts: 43
Quote:
Originally Posted by kai0n7 View Post
Did they give you any information on what they did to fix it?


"Updated internals"

Sent from my SM-G920V using Tapatalk
Poetical1 is offline  
Old 08-29-2016, 10:05 AM   #13
Member
 
Join Date: Jun 2016
Location: Northern Virginia
Posts: 96
Well, that's... vague.

Have you shot it yourself since it came back? Any noticible difference in trigger pull weight?
kai0n7 is offline  
Old 08-29-2016, 10:08 AM   #14
Senior Member
 
ThnkFrst's Avatar
 
Join Date: Mar 2012
Location: SEMI
Posts: 8,088
"Updated internals"? That's pretty nondescript even by SIG standards. Do you know the build date on your 938?

There have been a number of reports here on ST of "hammer follow", a.k.a., "hammer doesn't stay cocked". In many cases SIG has replaced sears and/or hammers. My recommendation is to contact SIG and have the pistol returned and repaired under warranty.
ThnkFrst is online now  
Old 08-29-2016, 10:32 AM   #15
Member
 
drband's Avatar
 
Join Date: Sep 2015
Location: GA
Posts: 96
P938 random malfunction

Quote:
Originally Posted by Poetical1 View Post


"Updated internals"

Sent from my SM-G920V using Tapatalk


This looks like my best solution. I will contact Sig and see what their response is.

It sounds like my exact issue.

I will update with developments.

My build date was late August 2015 if I remember correctly.
drband is offline  
Reply

  SIG Talk > SIG Sauer Forum > SIG Sauer Pistols > P238, P938 Pistol

Thread Tools
Display Modes


Similar SIG Talk Discussions
Thread Thread Starter Forum Replies Last Post
P938 Army or P938 Combat IMPD2079 P238, P938 Pistol 20 03-05-2017 01:59 PM
P938 Nitron Range Report, Part 2: VZ Grips and the New Federal HST 150gr. “micro” MG1964 P238, P938 Pistol 22 10-02-2016 12:15 AM
Handgun 103 with P938... Observations... PaleoMan P238, P938 Pistol 7 08-26-2016 10:08 AM
P938 Defense Ammo Testing TornadoHands P238, P938 Pistol 10 07-25-2016 12:59 PM
New P938 owner, also former P938 owner... kai0n7 P238, P938 Pistol 19 07-19-2016 03:02 PM


Top Gun Sites Top Sites List

Powered by vBulletin 3.8.7
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.6.1
Copyright © 2010 - 2017 SIG Talk. All rights reserved.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.SIG Talk is a SIG Sauer Firearms enthusiast's forum, but it is in no way affiliated with, nor does it represent SIG Sauer, Inc. of Exeter, NH.