I have a 27-2, 3.5 inch that has developed a problem. If I pull the trigger quickley in double action, or cock the hammer quickley in single action, the cylinder rotates past the chamber and if the trigger is pulled the hammer would strike the face of the cylinder between the two chambers. I believe this is called "jumping timing" but not really sure about that.

What is the cause and possible fix for this. Is it a worn cylinder stop. If it is the cylinder stop, can I replace it without doing alot of fitting. I have no problem removing/replacing the cylinder stop, but if it requires precise fitting I may send it to a smith.

Any help would be appreciated. I have had very good advice and help here (fixed a push off problem on my 15-3 with the help of this forum). I have said it before, but I will say it again. This is the best gun forum on the net!

The first thing I would do is put a red tag on the trigger guard as a reminder that it's not safe for live fire. Timing problems like this can lead to a blown up gun, so don't take any chances with that happening.

The second thing I would check is to see if the cylinder stop needs a good cleaning and a drop of oil. It's quite possible you have some old oil that has basically turned into "gum" and a good cleaning is all it needs.

Next I would put on some high power "readers" and take a good close look for any wear, rub marks, or indication that parts need replacement or fitting. If parts do need fitting, I would personally be inclined to send the gun into S&W for service. Revolvers aren't as common as they used to be and I'm not real trusting of finding a gunsmith who can do the work as well as S&W can.

As for fitting something like this yourself, this will require specialized tools and a high degree of skill. Since it's a real safety issue, IMO your better off sending it home and getting it done perfectly. Your 27-2 is a high value gun and it's worth spending a few bucks on it if it needs work. Another plus for sending it in is that they will fix anything that isn't perfect, so you'll get a basically new gun back ready for many many years of shooting.

PS, don't have a model 27 yet but one day I will. Fact is that the detailing that went into the model 27's can't be found today and you have a real Classic that someday may approach the renown held for the original Registered Magnums. Get it fixed right and please don't blow it up.

Might just need a cylinder stop spring or the existing spring could have gotten out of alignment

Sounds like the cylinder stop may need replacing or refitting. Normally the stop travels down and away from the cylinder as the gun is being cycled and rises back to touch the cylinder in time to drop into the next notch.

If the stop is missfitted, it rises too late, and when the gun is cycled fast, it will sometimes completely miss the next notch. This allows the cylinder to rotate too far and out of alignment so when the hammer falls, it will strike just about anywhere.

OR needs cleaning badly, OR needs the cylinder stop re-fit or replaced, OR the stop notches could be badly battered and the cylinder needs to be replaced. OR, OR, OR......
I don't intend to be demeaning, but the fact you asked the question means you don't have the current ability to repair this or you could diagnose it yourself. Trying to make such a repair based on the conjectures of people who have not had the opportunity to examine the revolver is not a good idea, and could be quite costly, both financially and in terms of safety. Do yourself a favor and either find a local gunsmith qualified to repair S&W revolvers or send it back to the factory.

I forgot to add in the orginal post that I am not the orginal owner of this fine revolver and it is a shooter with no real collector value (it has been refinished in hard chrome, addressing some pitting issues in it's past).

scooter123, I took a magnifying glass and took a good look at the cylinder stop and cylinder stop notches for excessive wear. I compared to them to my 29-2, which locks up tight and has no issues with timing. Everything looked good, no signs of excessive wear or peening.

Texas Roots, I took your advise and opened the cylinder, pushed back in the thumb latch and cycled the trigger and observed the cylinder stop. It rises immediately as the trigger cycles. I compared the rate of rise to my 29-2 and noted the 29-2 snaps up very quickly and the 27-2 snaps up not near as forcefully. Time to remove the side plate and take a look inside.

ken158, Hello my friend. To all who have read this thread, this is the man who helped me fix my 15-3 push off. Thanks again for all your help! I removed the side plate (for the first time on this revolver since obtaining it) and man the internals need a good cleaning. The cylinder stop spring is still in correct alignment, but like the rest of the internals it is very dirty. I suspect it may have also weaked over time. I plan to give everything inside a good cleaning and light lube. If that does not fix the problem, I will replace the cylinder stop spring. If that does not solve the timing issue, then it is off to the local smith.

Alk8944, I read your post and to quote you, "I don't intend to be demeaning", but I found nothing of value in it.

Thanks again for all the help. I am hoping a good cleaning or a cleaning/spring replacement is the fix. If that does not work I will drop it off at a local smith who I trust and does very good work at reasonable prices. I will keep you posted on the results.

I took all the internals out and gave them a good scrubbing with Breakfree CLP and a nylon brush. Got it all back together and tried to duplicate the timing malfunction. Right away I noticed the cylinder stop was much more positive on the up rise. It now locks up tight and I cannot get it to jump timing no matter how quickly/abruptly I cycle the trigger in double action or the hammer in single action. The cylinder stop spring has a slight bend/kink in it, so I will order a new one and replace it anyway. I think I will add a few cylindern stop springs and maybe a couple of rebound springs too. I do not want to pay shipping and only order one cylinder stop spring .

Thanks again for all the input. I am a certified armorer on Colt M-4s and Glock pistols and can trouble shoot, diagnose, and fix almost anything on those two weapons. I am new to revolvers, only recently being infected with the S&W virus. I can fix the small stuff, but diagnosis is my problem. I appreciate the help.

ken158, I am real close to owing you a smithing fee. You have saved me twice!

ken158, I am real close to owing you a smithing fee.

I remember some time back I needed an elevation nut for an N frame rear sight and posted WTB in the classifieds and ken158 mailed me one before he even got the funds from me. I always remembered that. He is very helpful here on the forum.

I hate to see a fellow like Alk8944 get chastised for speaking the truth. CQB27, If you were not up to cleaning the revolver before coming up with all the questions it makes me wonder what kind of armorer's course(s) you have received.

Sounds like you need a new spring for the stop.

Dan Cash, all due respect to you and Alk8944, I can see no reason to make a post that is not helpful.

Just the opinion of one old fart.

__________________
the world is round everywhere

Alk8944
You took the words right out of my mouth!

__________________
Doug