Why did S&W drop the "fourth" screw?

[aterry33]

I understand that the "fourth screw" or the screw in front of the trigger guard held a spring plunger that provided power to the cylinder stop or cylinder bolt.

Why did S&W eliminate this and go to the three screws that we still have today?

 

[jbouwens]

Like most things in life it is a matter of less parts= Less cost= more profit.

 

[Doc44]

The new cylinder stop (authorized on 11/28/61) eliminated several manufacturing steps and at least two parts including the cylinder stop plunger filler screw (or fourth screw). I am sure it did reduce manufacturing cost while not affecting overall quality or performance. Probably, similar reasoning was used to eliminate the large screw at the top of the side plate (authorized on 9/7/56) in favor of a tongue that interlocked with the frame resulting in the three screw side plate.

Bill

 

[aterry33]

So I can see how they replaced the "fifth" screw with an internal part, so to speak, but was that basically what they did with a redesigned cylinder stop, eliminating the need for the "fourth" plunger screw?

I guess I am just confused as to why S&W would have put a fourth screw there in the first place if it wasn't ever really necessary.

 

[gerald mcdonald]

So I can see how they replaced the "fifth" screw with an internal part, so to speak, but was that basically what they did with a redesigned cylinder stop, eliminating the need for the "fourth" plunger screw?

I guess I am just confused as to why S&W would have put a fourth screw there in the first place if it wasn't ever really necessary.

Designs change as years pass, it was a design from the late 1890's so as advancements are made things change. A better mouse trap so to speak. Had they thought of it in the 1905 version they probably would have changed it then if the money and time saved was worth the cost of retooling.

 

[Doc44]

Aaron...the screw was necessary. If you can find a copy of the History of S&W by Roy Jinks, look on page 221 as it has a great drawing of the old style and new style cylinder plunger stop. It will answer all your questions and more.

Bill

 

[aterry33]

Aaron...the screw was necessary. If you can find a copy of the History of S&W by Roy Jinks, look on page 221 as it has a great drawing of the old style and new style cylinder plunger stop. It will answer all your questions and more.

Bill

Thanks Bill I will look that up tonight.

 

[50 target]

JBOUWENS got it right. If you think of the units they push out the door every year, time is money and extra parts is money. Each engineering change you see could probably be chased to an engineer with a better idea that is hand in hand with the tooling capabilities at the time.I remember talking to an old experienced S&W collector back in the early 80's ( He is deceased now) and he told me that when the diamond was eliminated on the grip panel, they saved a penny each panel. Doesn't seem like much but if you pump out 250m guns each year that is $5,000.00 more to the bottom line and remember they are a business, they just happen to be in the business of making items that drive us crazy with questions and lust. Or am I just speaking for myself ? Enjoy them while you can.

 

[aterry33]

50 target, I agree for the most part, but I think some of the modifications were purely cost-cutting (like the yoke retention system in the 1980s) while some addressed a real problem, like the "-2" changing of the extractor from a right hand to left hand thread, because prior to that the extractor screws in Model 29s were coming unscrewed under heavy recoil and the cylinders were locking up.

Bill: I checked out the diagram in the Jinks book. That gave me a better understanding of the mechanics, but it didn't explain why the change was made other than to say it was an "improvement." I'm guessing that someone figured out you could ditch the plunger and extra screw/hole in the frame and just use an internal spring? This would be both an improvement in design (less parts to break) and cost-saving (less steps in manufacturing)?

 

[Bullet Bob]

I think that in general, less holes and screws from the outside of the gun to the innards is an improvement. One less screw to loosen and/or lose, one less place for moisture or other harmful agents to enter. Function has not been compromised, so there's no downside.

 

[Doc44]

Aaron...except for changing the extractor rod threads from right to left-hand resulting in the -1 model variation (the -2 was the change to improved cylinder plunger stop), I believe all the changes (including deleting the counterbored charge holes and the barrel pin) were steps to improve the manufacturing process and reduce costs. S&W is just a manufacturer and one of their objectives is to keep costs to a minimum.

Bill

 

[SaberOne]

Everyone seems to come to the same conclusion of cost savings. The new plastic Bodyguard is just a stone throw away from a recycled milk carton.

 

[H Richard]

What I don't understand is a 38 M&P 1st model had no hole in the trigger guard, and had the spring in a recess similar to current design. (A pre 5 screw 4 screw). Why did they not continue this?

 

[aterry33]

Aaron...except for changing the extractor rod threads from right to left-hand resulting in the -1 model variation (the -2 was the change to improved cylinder plunger stop), I believe all the changes (including deleting the counterbored charge holes and the barrel pin) were steps to improve the manufacturing process and reduce costs. S&W is just a manufacturer and one of their objectives is to keep costs to a minimum.

Bill

Bill, that's basically what I was thinking but I wanted to make sure I was on the right track.

Do you know of any cases of the old plunger system breaking?

 

[Doc44]

Aaron...I have never heard of either type causing a problem, but I don't believe the question has every been asked. If you are going to Tucson, you might ask Roy. If anyone would know, he would.

Bill

 

[aterry33]

Aaron...I have never heard of either type causing a problem, but I don't believe the question has every been asked. If you are going to Tucson, you might ask Roy. If anyone would know, he would.

Bill

Thanks Bill. I guess the real problem was the extractor threads coming unscrewed before they switched from RH to LH threads with the dash-1 modification, right?

I wonder if this problem was limited to the 44 magnums or if other calibers had the problem as well. I know that they made the change on all models.

 

[Doc44]

Aaron...Apparently, the problem with the 44 Magnum prompted the change, but it could have happened infrequently with the .357 Magnum (Combat Magnum, also introduced in 1956, comes to mind). S&W authorized the change on December 22, 1959, but it took over two years to implement it for the 44 Magnum, and really about three years since all but two Model 29-1s (shipped in late 1962) located thus far have extractor rods with the old style or right-hand thread and the 29-2 (three screw frame and extractor rod with a left-hand thread) started shipping in late 1962, but large quantities did not ship until early 1963.

Bill

 

[aterry33]

Aaron...Apparently, the problem with the 44 Magnum prompted the change, but it could have happened infrequently with the .357 Magnum (Combat Magnum, also introduced in 1956, comes to mind). S&W authorized the change on December 22, 1959, but it took over two years to implement it for the 44 Magnum, and really about three years since all but two Model 29-1s (shipped in late 1962) located thus far have extractor rods with the old style or right-hand thread and the 29-2 (three screw frame and extractor rod with a left-hand thread) started shipping in late 1962, but large quantities did not ship until early 1963.

Bill

I wonder how frequently this happened... I have shot tens of thousands of rounds through my four screw revolvers since I was a kid and have never had a screw come unthreaded. I know it did happen with the 44s and 357s. Someday maybe I will ask Roy Jinks how likely it was to occur. It's not something I worry about, I just find all of the design changes fascinating.

Thanks again for all the info Bill.

 

[Nellybelle]

Help me understand what part is "recessed" I keep reading about? Also is that a standard production change on all models? I am new here and would like to know about what you are speaking.

 

[Muley Gil]

Welcome to the Forum, Nellybelle.

"Recessed" refers to the rear of the cylinder on magnum and rimfire revolvers. On most S&W revolvers, if you look at a loaded cylinder, you can see the case rims. Not so on recessed cylinders.