S&W 52-2 Doubling

Occasionally, in sustained fire, the hammer falls during recoil recovery at the start of the next trigger squeeze. Usually puts that bad shot in the 12 o'clock white zone!
Any ideas on what causes this, and a solution?

Yes. I inherited my father's. While I'm not a gunsmith, i did stay at a Holiday Inn Express, figured out the problem and repaired it. I learned a lot about how the 52 works and how to replace the sear spring (which was not the problem)

It was really sneaky, so may not apply to your problem.  What's the history of the gun?  Any other issues of any kind that you may have or have had?

Front a 2006 thread on Target Talk:

i would start with a good cleaning first. dirt can casue a sear not to fully engage on some pistols.

possible causes of hammer follow through on the mod 52:

the model 52 uses a flat spring for the sear spring. it may be weak or broken.

the hammer spring may be weak

the sear nose may be blunt from letting it fall to half cock too many times

the hammer hooks may not be square or there is dirt in the hammer hooks causing the sear not to engage fully

worn hammer and sear pins causing the hammer and sear to wobble on the pins in turn causing poor alignment of the sear nose and hammer hooks.

the trigger return spring is worn casuing inertia to slap the sear on recoil which in turn leads to hammer follow through. to test this, hold the trigger forward . lock the slide open with the slide stop and let the slide slam forward. do this again this time without holding the trigger forward. if the hammer falls to half cock then you have a trigger bounce problem.

if you no hammer follow through, you may have a problem with the firing pin such as a weak or broken pin spring or dirt in the firing pin tube causing a slam fire.

another thing to check is the overall length of your disconnector and the cavity under the slide. if the cavity the disconnector rides in is filled with dirt it can lead to problems. if the disconnector head is worn out, you can have problems.

clean the gun first. use lots of gun scrubber and be sure to get in the trigger assembly nice and good. test for hammer follow by locking the slide open and letting it slam forward by releasing the slide stop. do this 6 or 7 times holding the pistol lightly (but firm enough as to not drop the pistol) if the hammer follows then you have a problem related to sear engament or trigger bounce. if it does not follwo through then suspect firing pin problems. pull the firing pin out and inspect the spring and really give the tube a good cleaning.

at any rate, if you cant get it figured out, send it off to a good smith.

RodJ wrote:Yes. I inherited my father's. While I'm not a gunsmith, i did stay at a Holiday Inn Express, figured out the problem and repaired it. I learned a lot about how the 52 works and how to replace the sear spring (which was not the problem)

It was really sneaky, so may not apply to your problem.  What's the history of the gun?  Any other issues of any kind that you may have or have had?

I bought the gun used, and the only major issue was replacing and fitting a new Clark barrel in it, but that was thousands of rounds ago.

NukeMMC wrote:Front a 2006 thread on Target Talk:

i would start with a good cleaning first. dirt can casue a sear not to fully engage on some pistols.

possible causes of hammer follow through on the mod 52:

the model 52 uses a flat spring for the sear spring. it may be weak or broken.

the hammer spring may be weak

the sear nose may be blunt from letting it fall to half cock too many times

the hammer hooks may not be square or there is dirt in the hammer hooks causing the sear not to engage fully

worn hammer and sear pins causing the hammer and sear to wobble on the pins in turn causing poor alignment of the sear nose and hammer hooks.

the trigger return spring is worn casuing inertia to slap the sear on recoil which in turn leads to hammer follow through. to test this, hold the trigger forward . lock the slide open with the slide stop and let the slide slam forward. do this again this time without holding the trigger forward. if the hammer falls to half cock then you have a trigger bounce problem.

if you no hammer follow through, you may have a problem with the firing pin such as a weak or broken pin spring or dirt in the firing pin tube causing a slam fire.

another thing to check is the overall length of your disconnector and the cavity under the slide. if the cavity the disconnector rides in is filled with dirt it can lead to problems. if the disconnector head is worn out, you can have problems.

clean the gun first. use lots of gun scrubber and be sure to get in the trigger assembly nice and good. test for hammer follow by locking the slide open and letting it slam forward by releasing the slide stop. do this 6 or 7 times holding the pistol lightly (but firm enough as to not drop the pistol) if the hammer follows then you have a problem related to sear engament or trigger bounce. if it does not follwo through then suspect firing pin problems. pull the firing pin out and inspect the spring and really give the tube a good cleaning.

at any rate, if you cant get it figured out, send it off to a good smith.

WOW! Thanks for the detailed response! Gave it a good cleaning, ran 100 rounds through it with no problem, so maybe problem solved.
Time will tell, but thanks again!
John

Awesome list from NMMC. Fyi my issue was chip in sear nose. How that occurred was due to trigger over travel set screw being set with marginal over travel such that sear nose wasnt clearing half cock notch. And TOTS screw was set so marginal because any deeper and it interfered with magazine insertion.

Glad it's resolved and hopefully no sear damage.