Are unfluted cylinders stronger?

Well are they? :) I'm lookin' at a S&W in .45 with an unfluted cylinder. Will it take higher pressure loads?

No, these days it's basically just cosmetic. Fluted cylinders will cool slightly faster since they have more surface area but it makes no difference about strength.

The weak point is still going to be the bolt stop notch which on the S&W's is directly over the chamber.

Yup.

In a Ruger with offset notches, there's a very small theoretical strength upgrade in unfluted. The gunsmiths doing five-shot customs in 454/475/500/etc are all doing unfluted, as far as I know.

Any bets on wether the 5 shot conversions are unfluted simply because it's easier to make a round cylinder than it is to carve the flutes out? :D

But the most important factor we have found here is there is very little difference in strength between a fluted and non-fluted cylinder. The strength of the cylinder can vary more from the quality of the material, the tensile strength of the part due to different points of hardness. When steel is heat treated it can easily vary a couple of points. This is only a few thousand pounds of tensile strength but this is likely to mean more to absolute strength than the difference in the design of the part in the argument between "fluted" or NON-Fluted".

John Linebaugh
http://www.sixgunner.com/linebaugh/dissolving.htm

Amen.

If you took the engineering drawing of the cylinder, put the point of a compass in the center of the chamber hole, opened it to touch the nearest edge of the cylinder, and drew a circle, only the metal inside that circle would affect strength.

The reason is simple -- if she's going to blow, she's going to blow at the thinnest point.

Jeff Cooper once said that in the only test to destruction he knew of the Ruger SBH blew up before the S&W M-29, but that since the pressures were approaching triple the normal, he considered the matter academic.

I just had a wild thought for you guys to ponder as I will continue to. Is it possible that fluted cylinders are actually stronger than non-fluted? My reasoning is this: steel is brittle, some steels being much less brittle than others, nonetheless it is brittle; also steel is extremely elastic. Given those two attributes, perhaps the fluted cylinder will allow the chamber to expand ever so slightly more under extreme pressure than a non-fluted one and the elasticity of the steel will bring it back to its original shape with no noticable deformation. The short term deformation may keep the cylinder from cracking when the non-fluted cylinder might do just that at the same pressure level.

There are many analogies to the principle I'm talking about. A steel bridge comes to mind. If the steel trusses and girders were shaped so that deformation wasn't possible, that bridge wouldn't last very long under high and variable loads.

As Vern points out .. indeed the weakest spot always has to be the outermost area of cylinder ... directly over the outer portion of any one chamber. That in turn made more so by virtue of cyl notch depth and placement relative to chamber center axis.

I throw in this ultra crude diagram ..... and you can see that area marked. Furthermore, the areas to each side of a chamber (material between chambers) is invariably AS thick or thicker. As each chamber only (we hope!) fires individually, that material to the side is available exclusively for one cyl, as if its neighbor did not exist.

This diag represents maybe a large cal 5 shot .... so this area is very generous .... the two lines showing what is available for currently the top cyl. The areas where fluting could be machined you can see are way ''material rich'' and so not contributing to burst resistance. Imagine Vern's circle he describes ... it is actually redundant material ...... fluting then in fact just lightens the whole cyl a bit.

http://www.patriotnetwork.net/cb_gun/cyl_wall_thin.gif

I have always liked the look of the non-fluted since my brother got his .44 Ruger Super Blackhawk..

Didn't S&W once make a M29 with a non-fluted cylinder and full barrel lug?? 6' or 7' barrel.. Called the 'Classic Hunter' or something like that... GOOD looking gun...

As to the strength, P95Carry's diagram tells me that as long as the flutes are cut on the area between the chambers, and not too deep, the strength should be unaffected.. I WILL increase surface area though, which should help cooling... :cool:

..my $.02...

-R

As a mechanical engineer who designs springs for a living, let me try to offer some insight.

Think of a diving board, when you're standing on the end of it. There's virtually no material directly under you, yet it does support your weight. It's flexing of course, due to the long cantilever effect.

The stress a gun's chamber is subjected to is very complex - it's partly hoop stress, partly impact loading, and partly shock wave in nature. There are engineering software packages that will analyze these stresses and tell you theoretically the weakest point on the cylinder.

Yes the Bolt notch is the thinnest point on the cylinder, but it is still supported by surrounding metal, much like the diving board supports you even when you're standing on the very end.

Without actually analyzing one, or testing to destruction, I would bet that an unfluted cylinder would on average tolerate a little more pressure than a fluted cylinder. Of course by the time you proved it you'd be scraping out melted brass out out of the chamber, too.:what:

I have seen a blown Super Blackhawk, which was on display for years at the San Leandro, CA Optimist Club range. The whole cylinder is split in half, and the frame is bent.

I think the best reason for unfluted cylinders is to give you a nice place to engrave reclining nekkid ladies, big deer, and other important scenes.
:evil:

I think the best reason for unfluted cylinders is to give you a nice place to engrave reclining nekkid ladies, big deer, and other important scenes. Always felt same way ...... such space for artistry!

tex_n_cal ....... any thought re this thread I started?

http://www.thehighroad.org/showthread.php?s=&threadid=24977

No takers as yet but .. seeing as you are into the field of springs .... wonder if you have made any for your guns?? Despite my metallurgical background (much as yours maybe, tho older!) ..... it makes little difference to succeeding with that ''black art'' ..... leaf types of course being the demons!

No takers as yet but .. seeing as you are into the field of springs .... wonder if you have made any for your guns?? Despite my metallurgical background (much as yours maybe, tho older!) ..... it makes little difference to succeeding with that ''black art'' ..... leaf types of course being the demons!

see my comments there:)

I make the comment there, I've been making them for 17 years, and the damn things still surprise me from time to time:)

Thx tex .... on my way .... :)

Will it take higher pressure loads? Higher than what? SAAMI? or do you mean will it take Ruger - T/C only class loads? If the former, then probably,,,if the latter then nope.

Mal,
Kinda like a fuller groove in a blade?
Hmm,,,maybe..

RE: The bolt stop placement. It ain't my theory as it seemed to be ascribed to me in another thread. I do however lean towards it. I saw my fat brother in law's leg sticking out of the ceiling @ my in laws one afternoon. He was running the cable for the TV antenna and stepped on the thinest part of the ceiling ('tween the joists).

If it gonna go, then it's gonna go @ the thinnest point, and the thinnest point of the thinnest part is the bolt stop.