Ruger SP101 22 gap between yoke and frame

[jski]

I noticed on my wife's SP101 22 revolver there's a small square spacer welded to the frame so that when the cylinder assembly is up (secured in the frame), there's a small gap between the yoke and the frame.

What's the deal with this?

 

[JohnKSa]

It's not welded on, it's cast as part of the frame and then machined to the proper dimension.

The cylinder has to line up perfectly with the barrel when it's latched. Ruger implemented that alignment requirement by casting a spacer/pad as part of the frame and then machining it to the proper "height" to insure that when the cylinder is latched into the frame it's aligned properly.

 

[jski]

One question, since S&W doesn't do this and there's consequently no gap between the yoke and frame, is Ruger's design/solution a better one? Or is S&W's design better?

 

[JohnKSa]

They both achieve the same thing different ways. From the shooter's standpoint I don't believe there's a practical difference. Since the gap can't be seen with the cylinder closed, there's not an aesthetic difference either.

If you're worried that the gap introduces some weakness into the design, don't. The SP101 design holds up very well to the .357Magnum cartridge. The cylinder lockup is quite strong and although there's a gap, there's steel-to-steel contact insuring proper alignment.

My guess is that Ruger's method is cheaper and simpler to manufacture.

 

[jski]

Didn't Savage introduce the barrel nut to simplify the design and reduce production costs? And isn't Savage's barrel nut design the reason their 111 rifles are the most accurate rifles out of the box?

 

[JohnKSa]

Right, there's not necessarily anything wrong with cheaper and simpler. This may be one of those cases. I've not ever heard anyone attribute any failure or practical problem to the Ruger implementation. In fact, I can't recall anyone ever bringing it up before.

I don't see this particular design decision making the Ruger stronger, more durable or more accurate. It's just a different way to do things--they do one simple machining operation to get the alignment right instead of having to carefully control the dimensions of the frame and yoke in that area to insure alignment.

 

[jski]

As an engineer I can say one thing for certain; given 2 solutions for the same requirements, always prefer the simpler solution. The Occam's razor of engineering.