Why is there a larger gap between the front of the cylinder & the frame on some guns?

C

C0untZer0

Moderator
I notice it on this CzechPoint 9231, the S&W Model 625 has it, as does the Model 27. Other revolvers have almost no gap in the frame window.

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All mass produced products are made to tolerances; if that were not so, each part would have to be made by hand and the cost would be prohibitive.

The barrel/cylinder gap will usually be held within a range of .003"-.010", with an ideal of about .006"-.007".

Much over .010", and too much gas is lost and velocity drops, as well as a lot of flash and fire from the gap. Under about .004", the cylinder will lengthen enough to bind as it warms up from firing.

Jim
 
shorter cartridge for a larger frame window equals less freebore,for more accuracy.
The 625 ,and model 27 are both on the large N frame,and the 625 is the short 45 acp round,while the 27 is 357 mag,but not that short.
 
If your sepaking of how the cylinder looks almost too short for the frame, it is, from the few examples I have seen, a shorter cylinder for a shorter cartridge, in a common sized frame. On these revolvers the barrel will be farther in the frame to ensure proper cylinder/barrel gap.
 
I was talking about how far the forcing cone came back into the window.

So for this CzechPoint 9231 it's because they are using a 9mm sized cylinder in a standard 357 magnum frame?

But then, why is it like that on the S&W Model 27? First of all, that's a standard 357 magnum cylinder to begin with. And secondly, that's one of their flagship models, surely they could have designed the frame to fit the cylinder?
 
Sorry for the misunderstanding. In theory, each cartridge could have its own frame and cylinder. And in theory, General Motors could made a separate auto body shape for every human body shape. But, AFAIK, they just make the seats adjustable.

The cost of frame manufacture is so great that it just is not practical to not use a single frame size for as many calibers as reasonably possible. While there are drawbacks, they are small compared with the excessive cost of making dozens of different frame sizes.

Jim
 
But then, why is it like that on the S&W Model 27? First of all, that's a standard 357 magnum cylinder to begin with. And secondly, that's one of their flagship models, surely they could have designed the frame to fit the cylinder?
Click to expand...

The Model 27's ancestor, the Registered Magnum, was built on the standard S&W N-Frame which was originally designed for .44 Special. While the .357 Magnum uses a longer case than .44 Special does, the maximum OAL of the cartridge is actually shorter at 1.590" as opposed to the 1.615" max OAL of .44 Special. When the Registered magnum was introduced, it actually used the same length cylinder as the .38/44 Heavy Duty and Outdoorsman revolvers which used a high-pressure version of .38 Special. Rather than design a new cylinder and/or frame, S&W chose to simply deepen the chambers a bit to accommodate the new cartridge. This practice has continued on with newer N-Frame .357's including the Models 27, 28, 627, and 327.

Later, when the K-Frame was adapted to .357 Magnum, S&W chose to also lengthen the cylinder and has done so with their L-Frame and J-Frame .357 Magnum revolvers as well. This leads to what is actually a rather peculiar situation: while the N-Frames are arguably the strongest of all S&W .357 Magnums, they cannot be used with certain bullets that work fine in others, such as the 173gr Kieth bullet, unless the bullets are loaded in .38 Special cases due to the cartridge's OAL.
 
As was said, a 625, and a 27/327/627, is based off the S&W 44mag frame.

But look at the newer Taurus 905's, a 9mm snub.

They use a .38spl sized frame, with a .38spl sized length cylinder. Overbored to the 9mm length shell's, 9mm shell's are wider than the .357 shell at the rim. Trust me.

At one time, correct me if I'm wrong, they (905) once had, either a shorter frame, or a shorter cylinder to what we are talking about in proportion's (There I go again, with aspect ratio's, again). "The big gap's"
 
Webleymkv Post# 8


while the N-Frames are arguably the strongest of all S&W .357 Magnums, they cannot be used with certain bullets that work fine in others, such as the 173gr Kieth bullet, unless the bullets are loaded in .38 Special cases due to the cartridge's OAL.
Click to expand...

OAL? Over all length?

Darn you Webley, you keep me thinking all the time.:mad:

I have some Corbon 200gr HCFN they fit all my .357s. SW327, 627, SP101, and forgive me a Rossi 461. But I tell you, they come right to the end of the cylinder holy thingy's. Never seen a 173gr Kieth before.:eek:

There you go, getting me off topic again.:mad:

TBS, my 200g .357 start to say "MaMa" next (Side by side)
to a Buffalo Bore 340g HCFN .44Mag +P+!:D
 
Well, since S&W designed the .357 Magnum, it is more likely that they kept its OAL within the length of the cylinder they had. Lengthening the chambers was required because they lengthened the case to keep it from being loaded into .38 Special revolvers, many of which would have been unsafe with the .357. That was also why they called it the ".357 Magnum" rather than ".38 something".

When S&W decided to use the basic I frame (which was used with .32 S&W Long and .38 S&W) for its new .38 Special Chiefs Special, they had to lengthen the cylinder, which also meant lengthening the frame, thus creating the J frame. The modern J frame has been lengthened and strengthened once again for use with the .357.

Jim
 
The shorter 9mm-sized cylinder (length-wise) with the barrel & forcing cone coming back in the window is a better design than using a 38spl sized cylinder which is longer than the 9mm cartridges right?
 
Typically you want to minimize the distance that the bullet has to travel before it hits the forcing cone and enters the rifling. That's why you see those S&W revolvers like the 625 with short cylinders and their barrels set farther back into the frame. The less free bore the better.
 
The shorter 9mm-sized cylinder (length-wise) with the barrel & forcing cone coming back in the window is a better design than using a 38spl sized cylinder which is longer than the 9mm cartridges right?
Click to expand...

Bottom line is that it's cheaper than making a new frame design for the smaller cylinder. I guess it works if you can stand the dumb looks of it, but I still don't understand the reason for a 9MM revolver. If the frame is the same size as a 38 Special, what's the advantage?
 
I've always wanted a 9mm revolver and I don't know why.

I didn't buy the Smiths or the Rugers when they were out and then they stopped making them and I regretted it.

I have been waiting and waiting and waiting and waiting for the Charter Arms rimless revolver in 9mm and it's still not here yet.

I'm not sure when Czechpoint started importing these Alfa-Proj revolvers but I just them this week, and the 9mm revolver may be my next purchase.

I just want a 9mm revolver.
 
Webleymkv said:
Later, when the K-Frame was adapted to .357 Magnum, S&W chose to also lengthen the cylinder and has done so with their L-Frame and J-Frame .357 Magnum revolvers as well. This leads to what is actually a rather peculiar situation: while the N-Frames are arguably the strongest of all S&W .357 Magnums, they cannot be used with certain bullets that work fine in others, such as the 173gr Kieth bullet, unless the bullets are loaded in .38 Special cases due to the cartridge's OAL.
Click to expand...

I noticed that too. Several years ago when I was playing with 180 grain cast bullets I loaded some and had a K-frame laying on the bench. I dropped a couple in the cylinder to make sure that the cartridge wasn't too long. A week later I was out with an N-frame and tried to shoot some of the new load. Too long, and I tied up the revolver. Yeah, K-frame cylinders are longer than N-frame cylinders. Go figure.

I've done the .38 brass trick too. Years ago, Skeeter Skelton was talking about it, so I gave it a try. It's very handy to be able to make .357 magnum pressure with .38 special brass. And no, I know what you're thinking. If you make them .357 length, no one will accidentally use them in a .38 special pistol. They won't fit. It's a trick that works fine if you find yourself short of .357 brass.
 
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