N-Frame cylinder stop notches, size varies, Why??

[Master Blaster]

A couple of days ago I asked about the changes to the S&W 629-2 denoted by the 2 and about the endurance package. The reply I received from one of our members was very detailed and mentioned that in the 629-3 the cylinder stop notches, and the stop, were enlarged to prevent unlocking in recoil with 300 grain silouhette loads.

So I went and pulled out my 629-2 and my old 1967 manufacture 27-2 my only other Smith N-frame. I expected that the 27-2 being a .357 mag, would have smaller stop notches than the 629-2, but boy was I surprised to see that the 27-2 cylinder stop and notches were 1.5x the size of those on my 629-2 which is 20 years newer and a .44 mag to boot.

The stop notches on the 629-2 are about the same size as those on my K frame revolvers. Now my 629-2 has an unfluted cylinder could this make a difference? (it would seem to me they would be bigger due to increased weight).

Just how important is the size of the stop and stop notch to the function and lockup of the revolver? How do they decide how big a stop and a notch should be?????

Thanks

 

[Old Fuff]

The dash numbers denote engineering changes. These changes weren't all made at the same time. So a certain dash-number on a particular model may not be related in any way to the same dash-number in another model.

The 27-2 change didn't have anything too do with the size of the cylinder stop notches in the cylinder, and was made during 1961. That came along in 1989 at 27-5.

The 629 incorporated the longer notches in 1989 at 629-3.

In a S&W revolver the cylinder stop move back and forth as well as up and down. High speed photographs showed that when shooting heavy loads it was possible for recoil to unlock the cylinder for a fraction of a second. to prevent this the notch was lengthened.

As long as you don't have a problem with this ... well you don't have a problem.

 

[Master Blaster]

Thanks FUFF, I did realize that the -2 in the 27 and the 629 dont coincide in any way. The two guns are 22 years sperated in manufacture date.

I just thought it odd than an older smaller caliber N frame gun
the 27-2, would have much larger cylinder stop notches, than a .44 mag Nframe made 20 years later. I expected the .44 mag would have larger stop notches.

 

[Old Fuff]

It is possible that S&W enlarged the notches in the model 27 cylinder a bit, but didn't assign a dash-number because the change didn't effect part interchangeability. They could do this because the cylinder walls are thicker on the .357. If so, I was unaware of it, but it won't be the first time. You might check with S&W and ask them.

 

[Fatelvis]

I just bought a used 629-3 Magnaclassic and was concerned if it had the endurance package, as I'm using it with heavy loads for silhouette competition. I called Smith and Wesson and asked them, and the Tech said that it didnt matter if the gun was a 29 or 629, all endurance packages started at -4. I looked at my cylinder notches, and they're longer and offset from the verticle notch, which I thought was a sign of the endurance package being present. Who is correct? Please tell me it wont shoot loose soon! Thanks-

 

[sigstroker]

High speed photographs showed that when shooting heavy loads it was possible for recoil to unlock the cylinder for a fraction of a second.

Yeah right.

No high speed photography was needed because when they unlocked, the cylinder rotated backwards. When the gun was cocked again the cylinder rotated to the chamber that was just fired, which was an empty casing. It's happened to me a few times with a friend's newer gun, but never my old one, oddly enough.