Model 66-2 weirdness!!!

[2336]

Folks,
I've got a model 66-2 and today had a really weird occurrance. I was firing 125gr jacketed soft point .357 mag ammo and had a heckuva stoppage. I had finished two cylinder's full, loaded the third cylinder full and started to fire. I got off two rounds and then the revolver just locked up! It locked up so tight that the cylinder wouldn't move and I ended up spending almost 30 minutes just trying to pry the cylinder free so I could unload and move off the firing line. I ended up prying the ejector rod detent forward and then pried up on the ejector rod before the cylinder sprang free. That was at about 11:00 this morning. When I got the cylinder free I noticed that the ejector rod showed no evidence of having backed out, and was NOT loose at all! Definitely could not turn it by hand! I checked it again this evening after the Super Bowl and no problem! The cylinder releases and locks back into place like nothing ever happened. This definitely shoots my opinions about revolver reliability all to crap. Any ideas folks??? I love to shoot this weapon but can't rely on it as a defensive arm after today. I've had ejector rods back out on me before but nothing as serious as what I experienced today. And nothing that locked up the weapon as tight, either. What really throws me for a loop is that it acts just fine now but a couple of hours earlier I couldn't even get the cylinder to turn just to fire.

 

[2336]

Folks,
I've got a model 66-2 and today had a really weird occurrance. I was firing 125gr jacketed soft point .357 mag ammo and had a heckuva stoppage. I had finished two cylinder's full, loaded the third cylinder full and started to fire. I got off two rounds and then the revolver just locked up! It locked up so tight that the cylinder wouldn't move and I ended up spending almost 30 minutes just trying to pry the cylinder free so I could unload and move off the firing line. I ended up prying the ejector rod detent forward and then pried up on the ejector rod before the cylinder sprang free. That was at about 11:00 this morning. When I got the cylinder free I noticed that the ejector rod showed no evidence of having backed out, and was NOT loose at all! Definitely could not turn it by hand! I checked it again this evening after the Super Bowl and no problem! The cylinder releases and locks back into place like nothing ever happened. This definitely shoots my opinions about revolver reliability all to crap. Any ideas folks??? I love to shoot this weapon but can't rely on it as a defensive arm after today. I've had ejector rods back out on me before but nothing as serious as what I experienced today. And nothing that locked up the weapon as tight, either. What really throws me for a loop is that it acts just fine now but a couple of hours earlier I couldn't even get the cylinder to turn just to fire.

 

[john traveler]

Did you shoot rapid fire for those 14 shots?

Did you examine your fired primers for sign of high pressure extrusion into the firing pin hole? That will certainly lock up your revolver.

What brand and lot of ammunition did you fire? Does that brand have a reputation for locking up guns?

 

[Rich S]

could soot/unburnt powder have been under the ejector star causing it to stick out and bind the action?

 

[Iggy]

john traveler has a very good point.

That was my first thought too.

 

[Ga Johnny]

I used to have a 19-3 that would do the same thing, mine was using 158 mags, primers showed no signs of over pressure, never did figure it out, never really tried to I guess. But I always suspected that heat created during rapid or sustained fire would cause something to expand enough to bind. It would always return to normal if given time to "cool" down, and never gave trouble with 38spl.

 

[likestoshoot2]

I had a problem like this before, Is it clean inside as is there any gummy build up in arm that advances the cylinder or anywhere inside for that matter, it just may need a good cleaning inside. Take the cover off and spray in some CLP or other cleaner do not use WD-40.
If your not commfortable doing this any good Gunsmith will do it.
Good luck

 

[2336]

Folks, the weapon was thoroughly cleaned prior to this firing session. Even made sure to double check the area under the ejector star. I was shooting UMC brand 125gr JSPs. On this box of 50 rds I had previously fired 18 rds with no problem. The first 14 rds of this shooting session were fired within an approximately 4-5 minute time frame. I was shooting fast but not "simulated combat scenario - fast". As far as bulged primers, by the time I got the cylinder loose I was too teed off to even think about checking but now that I think about it was probably the culprit. Especially since the ejector rod was still tight. Thanks for giving me a "clearer mind" perspective folks. To say I was angry earlier would be a heckuva understatement! I don't think I'll be using UMC ammo anymore.

 

[H Richard]

This problem was noticed in some "early" model 66's. The B/C gap was very close, and the specific type of stainless steel the cylinder was made of expanded due to heat build-up with hot loads. There was a fix, I'm not sure exactly what it was, but it should have been done before the -2 was produced. Could have been an old part still available when yours was made. When the guns cooled down, everything was "normal". Contact S&W and it should be still under warranty. I think there was a change to a different grade of stainless. Perhaps someone with a better memory than mine can recall.

 

[BruceM]

I take it that the hammer nose bushing has not pushed back slightly into the frame? I had a M29 do that and it allowed the primers to move backwards ever so slightly, locking up the whole gun.

Bruce

 

[KJACK]

I had the same thing happen with my M48 shooting CCI MaxiMags on Saturday. Froze up after 3 cylinders - frustrating! The cylinder gap is so tight I can barely see light through it when absolutely clean.

 

[Nightowl]

Check the bottom of the forcing cone to see if it has cracked. This has been reported to happen with 125 grain bullets. A long time ago, I cracked the forcing cone in a model 10 with SuperVel and it locked up the gun.

 

[Doug M.]

Originally posted by H Richard:
This problem was noticed in some "early" model 66's. The B/C gap was very close, and the specific type of stainless steel the cylinder was made of expanded due to heat build-up with hot loads. There was a fix, I'm not sure exactly what it was, but it should have been done before the -2 was produced. Could have been an old part still available when yours was made. When the guns cooled down, everything was "normal". Contact S&W and it should be still under warranty. I think there was a change to a different grade of stainless. Perhaps someone with a better memory than mine can recall.

*
This theory largely matches the experiences I had with a 649 back in the 80s. It would lock up (although not this badly) after 5-10 rounds. It was a heap; I sold it and moved on.

 

[Sgt 127]

Betting the primer flowed back into the firing pin hole. I've had it happen to me. Have you by chance doen an action job on the gun? Weaker mainspring? Backed off the mainspring strain screw?

 

[2336]

I just recently purchased the weapon used. Whoever had it before, in my opinion, certainly had it worked. As far as exactly what has been done - no idea. I can tell you this though, just a guesstimate but the single action trigger pull feels like 3lbs or less and double action feels like a very, very smooth 9-10lbs.
Really ticks me off though. This revolver shoots point of aim, point of impact. Beautiful shooter, just my luck to have problems with a handgun that shoots so sweet!

 

[Sgt 127]

Replace the mainspring strain screw and, your problem may go away. If the mainspring tension is too soft, the primer can flow back and push the firing pin out of the way. Try it again and look at the primers, the will have a little nurd sticking out that matches the firing pin hole.

 

[john traveler]

I second Sgt 127's suggestion. A weak or marginal firing pin strike will allow primer extrusion into the FP hole and lock up the gun.

This business of certain lots of factory ammo locking up revolvers does happen occasionally. Soft primers, weakened firing pin strikes, or hot loads can do this. Hot handloads are especially culprit.

The previous statement about early production M66 guns locking up with rapid fire applied to early production M19s too. The original gas ring design was located on the cylinder, was relatively thin, and absorbed firing heat rapidly, enough to cause binding of the cylinder when hot. Engineering changes moved the gas ring to the crane, giving it more mass and less likely to overheat and bind.

 

[2336]

Thanks for all of your input folks. I'll try it a couple more times and see if I get a re-occurance of the problem then go from there. Thanks again!