Strenght of 7 shot 686 cylinders?

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SIGfiend

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Since the 686 has been made to hold 7 shots instead of 6 now, it looks like the gap between each bullet chamber in the revolver's cylinder is very thin! Like maybe 1.5-2mm between the adjoining holes (anyone know the gap width on the 6 shot ones?).

If you shoot .357 magnums constantly and consistently through one, will the cylinder hold up considering the pressure it's being put through considering the thiness?
 
Yes; the space between cylinders is not the weakest point in a revolver, even in a 6-shot, and even less so in a 7-shot. Cylinder strength is not an issue here.
 
Right. To clarify: in the S&W six-shooters, the cylinder "bolt cutout" (the place where the thing jams up from underneath to lock it up goes) is right on top of each cylinder bore. This is a potential "weak spot". On the S&W 7-shooters, this notch is between cylinder bores so in theory, the 7-shooter might be the *stronger* gun.

(Ruger sixguns offset the notch between rounds...theoretically stronger yet.)
 
This is the common wisdom, but the only time I have heard reliably of a cylinder bulging or cracking through the cylinder stop notch(es) was in a gun rechambered from .357 to .44 or .45. On the other hand, I have seen many guns and photos of guns with the cylinders blown from double charges or powder ID error, and the whole top of the cylinder is usually gone, the blown chamber and the ones next to it.

But I would not worry about it in normal use. The steel is not being stressed beyond the yield point and is not going to "wear out" with continued firing with good ammunition.
 
Well yeah, the whole top of the cylinder will be gone, but where did the crack start?

There's a body of thought out there that says "bolt notch", even when the bolt notch area in question has been scattered across the range.

Look at it this way:

Bolt notch area on the firing cylinder starts to cut loose. First thing that happens? Lengthwise crack along the outside of the cylinder wall, where the bolt notch is (on the S&W six-gun setup anyways).

What THEN?

You've now got a "snapping twig" type pressure going along the cylinder walls to the ajoining cylinder bores. You've got a "compression problem" at the outer cylinder wall areas of the two ajoining cylinder bores right near their bolt notch areas.

Result? The entire outer half of the firing cylinder bore blows out, and the two ajoining cylinder bores are "exposed to the air" too. Exactly what we see.

But where did it all most likely start?

Bolt notch, firing cylinder.
 
Could be.
Let's blow one (of yours) up in a stout box and examine the pieces.

Or just recall what Jeff Cooper said about Smith vs Ruger strength. The only time (he knew of) a S&W and Ruger were tested to destruction, the Ruger blew up first, but since the pressures were approaching triple the normal, he considered the question academic.

And SIGfiend was asking about continued use, not overloads, and I don't think metal fatigue a factor in revolver use.

As long ago as 1909, W.W. Greener turned a shotgun barrel down to "about the thickness of a calling card" and shot it without rupture, after which "it was ripped up easily with a penknife." Gen. Hatcher had a .30-06 barrel turned down to 1/16" over the chamber. It shot service loads OK, but a proof load blew out a plug.
 
I've examined "range wreckage" of various guns kept at shooting ranges for their "do NOT do like this idiot did" value.

As to Cooper's observation, without knowing which models were involved it's pointless to speculate. If he was comparing an S&W K-Frame to a Ruger Service/Security series, that would be interesting but wouldn't necessarily have a bearing on GP100 vs. L-Frame. (And if any S&W J-Frame tested tougher than an SP101, I'll eat my motorcycle helmet.)
 
Range wreckage?
Pictures?
Yum.

Actually, Cooper was talking about M29 vs SBH, the question was, "Isn't an unfluted cylinder stronger than fluted?" Answer, "no."
 
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