Broken Hammer Block

[bountyhunter]

O.k. trend is starting.
Model 60-10.
Hammer block broke into 3 pieces while I was doing some dry firing.
Had a complete action job done from P/C. I installed a spring set, was testing it and the action completely locked up.
Took off the cover and 3 pieces fell out.

IMHO, that part needs to be removed if it is so unreliable and locks up your gun when it fails. The HB is a redundant safety to the rebound slide which blocks the forward movement of the hammer when the trigger is forward. The only time the HB is really needed is if the gun is dropped and lands on the hammer spur, breaking the hammer and driving it into the primer. I leave the blocks in my defense/carry guns but remove them from my comp and range guns since I don't drop my guns on the hammer. I keep them in my defense guns as lawyer proofing, since removing any safety could let some lawyer claim I intentionally made the gun "unsafe". Your choice, but if they keep breaking you can remove them.

 

[pinkymingeo]

MIM is an expensive process that S&W uses for parts that otherwise would need hand fitting. The hammer block doesn't fit the formula. I'd have to guess it's just a cheap cast part, not MIM.

 

[HalfSwiss]

That sure doesn't inspire confidence!

 

[johngalt]

Interesting picture. My 686-6 and 625-8 have MIM parts, but the hammer block in those are stamped and twisted 90 degrees. I don't understand how they could be breaking - they shouldn't be getting hit by the hammer, it gets moved out of the way by the trigger before the hammer falls.

 

[bmcgilvray]

Well, that's it and it sure is busted.

I can't tell from the photo the nature of the material from which it is fabricated. Hard to imagine why it would break like this.

 

[bountyhunter]

Interesting picture. My 686-6 and 625-8 have MIM parts, but the hammer block in those are stamped and twisted 90 degrees. I don't understand how they could be breaking - they shouldn't be getting hit by the hammer, it gets moved out of the way by the trigger before the hammer falls.

I suspect the piece does not fit the "channel" which is machined into the side plate correctly and the movement of the rebound slide is forcing the part and stressing it. I don't believe the hammer hitting it would break it, but the RB slide can exert a lot of force onto the end of the piece which is likely forcing it into a position where it runs out of room and then snaps from compression.

 

[thomasinaz]

I also had one of these break on a J Frame; a .357 caliber Model 649. It had a professional trigger job done to it and I did dry fire it a lot. Got a new one from Brownell's and never had another problem with it. Most of my other S&Ws are dry fired quite a bit, but this only happened on the 649. For what it's worth.....

 

[Dpris]

Famous last words: "I don't drop my guns on the hammer."
Denis

 

[Nyteman 44]

I was under the impression that pot metal parts were only limited to cap guns of the 40's - 60's

 

[PRM1]

Follow Up and Good News From S&W

S&W Customer Service has told me they no longer use the MIM hammer block. They also shipped me a new all steel bent version.

I guess this is a new fix, correctly done. A month ago they were still sending out the cast parts as replacements.