New S&W revolver question

[4V50 Gary]

So I recently saw a new S&W 45 AcP revolver. It had a thinner barrel much like an older production S&W. What struck me as odd is that the ejector rod shroud doesn't have a front locking bolt. OK, so they save three pieces (front locking bolt, front locking bolt spring, retention pin) and some assembly time, but why delete part of the lockup system?

Also on the older S&W revolvers the centerpin is pushed back by the front locking bolt such that the centerpin pushes back on the locking bolt (that connects to the thumbpiece/cylinder release).

Can someone explain the design changes?

 

[mete]

$$$ The bean counters demand lower costs and the customers demand lower prices .They should be demanding higher value .

 

[Scorch]

FWIW, the center pin is spring-loaded and moves to the rear under spring pressure. The locking bolt does not push the center pin back, a very cursory examination of the size of the two springs in question will confirm that. All the front locking bolt does is hold the ejector rod centered when the gun is fired, which I suppose keeps the crane assembly from wandering under recoil.

Another FWIW: Colt revolvers never had a front lock and they worked fine, except that once they started shooting loose they would get loose really quickly.

 

[Dixie Gunsmithing]

As Scorch states, that is all the front locking arrangement was for, to hold the ejection rod in place or centered. The lack of it will, most likely, cause it to wear out quicker. They did it over tightening the purse strings, and hoping that people will accept it. If it flies, look for it to happen on the other models.

 

[James K]

The original idea was that the cylinder rotated on an axis between two fixed points, the center pin hole in the rear of the frame and the locking bolt at the front which entered the ejector rod. (The fitting into the crane is almost incidental - the gun will function without the crane until you need to reload.)

The new system uses a ball bearing to lock the crane into the frame at the center point, so there is no need for all that mechanism at the front end. Better? I don't know, it seems at least as good, and certainly is less expensive. The original M&P (c. 1900) had no front ejector rod lock at all; the change was an improvement; whether the new change is an improvement, only time will tell.

Jim

 

[4V50 Gary]

Looked for and didn't notice any ball bearing lock up on the yoke/crane. I'll have to go back and look again.

 

[Dixie Gunsmithing]

The problem with a ball detent, to center the crane, is that every time you swing open and close the crane, the ball will create wear at the detent. It is sort of like a shifter, using a ball detent, loosening up in a transmission. I have seen lathe controls, using ball detents, loosen up after awhile, to the point they'll drop out. The continuous operation generally wallows out the detent hole.

Locking the extractor rod to a spring-loaded center pin (locking bolt), is akin to mounting a part in a lathe between centers. To me, it's a much better design, when compared to the way they're doing the locking now. It seems to me, to be a cost cutting gimmick, but I might be proven wrong on it.

 

[MrBorland]

Locking the extractor rod to a spring-loaded center pin (locking bolt), is akin to mounting a part in a lathe between centers. To me, it's a much better design, when compared to the way they're doing the locking now.

On the flip side, a bent (or slightly unscrewed) ejector rod on a S&W with an ejector rod lockup design can affect (or even tie up) the action.

One of the design strengths of the Ruger GP100, IMO, is that it locks up at the yoke and ejector rod, while the ejector rod doesn't turn as the cylinder does.

It's worth noting that to be effective, the ball detent has to be installed correctly. I've seen numerous ball detents installed by gunsmiths that were merely cosmetic.