Difference between fluted and unfluted cylinders

[sequins]

Hello Friends,

I was recently having a conversation with a buddy of mine about my revolvers. I'm pretty new to revolvers having only gotten my first revolver this year, and more recently my second. I happen to really enjoy the aesthetics of unfluted cylinders and so I chose a Super Blackhawk for my first revolver, which is unfluted, and then I got a special TALO edition of the Ruger GP100 so I could get that in an unfluted configuration as well.

So, here I am with my IMO very attractive looking unfluted revolvers and I'm showing them off to my buddy and he comments that I ought to stop being cheap and get fluted cylinders moving forwards. Cheap? I paid extra for the unfluted GP100! I asked him what he meant and he wasn't really able to articulate it except to say that fluted cylinders were well known to be "better" than crude unfluted cylinders.

That got me started doing some online research and I really struggled to find anything conclusive. I confirmed that there is definitely a heretofore unknown to me debate that was raging on the subject, but I could not find anything from any manufacturer- only forum conjecture and various unconfirmed claims. I'd like to get closer to the bottom of things and so I have a few specific "myths" I'd like to put forward for the thoughts, opinions, and hopefully valuable insights of the THR member community

-Fluted cylinders are more durable due to the ability of the cylinder chamber to expand in the direction of the fluting, rather than exclusively on the outer wall and webbing

-The most likely place to fail on a cylinder is the webbing between chambers, not the outer wall, and that's why big bore revolvers are 5 shots with a thicker webbing

-The reduction in cylinder weight achieved by fluting is significant, and an unfluted cylinder is much more likely to have timing issues, which would be exacerbated/guaranteed to happen "in rapid DA fire" (this myth is almost exclusively expressed with the "in rapid DA fire" qualifier so I'm including it here)

-Fluted cylinders give you a physical reference you can index with your fingers, allowing you to reload while looking somewhere other than your cylinder. *This is the only one that I think is conclusively true.

I'm particularly interested in the assertion that the extra weight will mess up the timing- That just seems pretty ridiculous because how many grams are we talking, even on a huge cylinder? I find it hard to believe the difference between reliable function and running out of time after a few dozen rapid shots is a couple of grams...

I'm also particularly interested why the Ruger Supers (Red/Blackhawk) are unfluted if a fluted cylinder is stronger. Same with the unfluted S&W performance center guns or say the 629, if fluted is stronger/better why would they be going unfluted on these guys?

What say you THR: Is the difference purely aesthetic or is there a functional argument for flutes being empirically superior? Any evidence to support a belief or prove/disprove any of the points I brought up would be appreciated!

 

[4thPointOfContact]

I've always thought that unfluted cylinders were a 'hunting' thing, where the extra weight of the cylinder helped control recoil. Aside from that I never thought there was a pro/con to them.

 

[Panzerschwein]

Unfluted cylinder add more weight to the firearm and are stronger than a fluted cylinder.

Fluted cylinder weigh less, and produce less wear on the bolt during fast firing due to the decreased mass of the cylinder impacting the bolt/cylinder stop at full momentum.

 

[sequins]

Does the cylinder spin faster if I shoot twice than if I shoot once? It seems to fully stop and lock up with each shot, so I'm curious why rapid fire would matter but slow fire wouldn't. Shouldn't they both wear the stop equally? I guess rapid fire might accelerate wear if the unfluted does in fact cause excessive wear, but I think it's all or nothing and slow shots do the same as rapid.

 

[jmr40]

Fluting the cylinder adds an extra step and a small increase in the cost of production. Originally most revolver cylinders were left unfluted. Cutting the flutes reduces weight and changes the balance of the gun without significantly reducing strength. IN theory unfluted is stronger, but just not that much. Over time fluting has become the normal procedure and today getting one unfluted is an added expense.

At one time most of the mainstream better quality revolvers were all fluted while many budget guns left them unfluted to help reduce costs. This may be what your friend is thinking about. It is no longer a sign of quality, if anything the reverse is true. Having all the facts can sometimes lead to the wrong conclusions and it seems this is what happened to your friend.

 

[MrBorland]

When shooting slowly in DA, I seriously doubt there'd be any difference wrt timing and peening issues.

And while I don't have hard data to support this, I suspect damage (timing and peening of the bolt and/or slots) from fast DA shooting is more related to trigger pull technique than weight of the cylinder.

When shooting DA quickly with poor technique, the initial phase of the pull is a very hard yank, which really accelerates the cylinder. This fast acceleration/deceleration can be tough on guns. Good DA technique, whether fast or slow, is where the pull is quite consistent from beginning to end. Much less strain on the gun. I have over 70k (most of it rapid DA) on one of my (fluted) revos, and it's still in time, and has no visible peening of the bolt or stop slots.

 

[CraigC]

Mostly myth. There is no strength difference. The Freedom Arms 83 is unarguably the strongest revolver available and they are typically unfluted.

The weight difference is almost insignificant. For large frame single action cylinders of the same chambering, the difference is only 0.3oz.

In theory, the greater inertia of the heavier cylinder causes greater battering of the cylinder stop and locking notches. Although I don't know if this has actually been proven.

-Fluted cylinders give you a physical reference you can index with your fingers, allowing you to reload while looking somewhere other than your cylinder. *This is the only one that I think is conclusively true.

This one is true.


Bottom line, if you like it, don't worry about it.

 

[mjsdwash]

fluting makes unloading a single action with a load gate much easier, since it can be done by feel alone. They weigh slightly more. There is really no difference on a swing out revolver. The weight dosent matter on your gp, since those weigh so much already. But if you get a single action, go for the fluting, it makes loading and unloading faster.

 

[45 Dragoon]

I've got to say, I don't know where folks get the idea that a solid cylinder would be weaker than a fluted . . . . .huh?

I will say after finishing a "Fanning '60" , the less material you're spinning, starting and stopping (in the blink of an eye) the better the tuner feels!!!

It's not the most natural thing to do but it can be done! It occurs to me that there is some truth in having less energy to deal with if the mass is concentrated inboard (fluted) rather than out board (non) in a cylindrical body. No matter how much more mass there may be, it is magnified many times by speed. Not to mention the energy needed to start and accelerate the same mass. (Still in the blink of an eye).

For the most part, you probably won't be fanning your Rugers so, I agree with Craig C
Get what you like !! (The rest wont matter!!)

Mike
www.goonsgunworks.com
Follow me on Instagram

BTW, timing is a purely mechanical thing.

 

[Japle]

I find the arguments against unfluted cylinders very unconvincing.

Personally, I like the look. I got S&W to install this cylinder on my 686SSR.

 

[Zaydok Allen]

So, here I am with my IMO very attractive looking unfluted revolvers and I'm showing them off to my buddy and he comments that I ought to stop being cheap and get fluted cylinders moving forwards. Cheap? I paid extra for the unfluted GP100! I asked him what he meant and he wasn't really able to articulate it except to say that fluted cylinders were well known to be "better" than crude unfluted cylinders.

Your buddy is mistaken and jmr40's comment is the likely reason. Your friend doesn't know what he is talking about.

-The reduction in cylinder weight achieved by fluting is significant, and an unfluted cylinder is much more likely to have timing issues, which would be exacerbated/guaranteed to happen "in rapid DA fire" (this myth is almost exclusively expressed with the "in rapid DA fire" qualifier so I'm including it here)

I think this is really an exaggeration and the only time it could be a concern would be rapid firing with poor trigger control of something with a really large and heavy cylinder like an X frame. Peening of the stop notches would be the most obvious result, and I suppose the pawl could show signs of ware and tare with enough trigger pulls.

-Fluted cylinders give you a physical reference you can index with your fingers, allowing you to reload while looking somewhere other than your cylinder. *This is the only one that I think is conclusively true.

Yes

The rest seem overstated. I like unflutted guns too.

 

[Driftwood Johnson]

Howdy

I have been shooting revolvers for over 40 years, and you have posted some stuff that I have never heard before. And some of it is pretty ridiculous.

-Fluted cylinders are more durable due to the ability of the cylinder chamber to expand in the direction of the fluting, rather than exclusively on the outer wall and webbing

File this one under ridiculous.

-The most likely place to fail on a cylinder is the webbing between chambers, not the outer wall, and that's why big bore revolvers are 5 shots with a thicker webbing

This is actually untrue. With most revolvers the thinnest section of the cylinder is the space between the chamber and the locking slot right above the chamber. I had a friend who used to be a line engineer at Ruger. One day they did some testing to see what it would take to blow up a Vaquero. Mind you, this was the older model Vaquero, which had a beefier cylinder than the current New Vaquero. He put the gun on a test stand, and kept firing heavier and heavier overloads in it until the cylinder burst. He captured the failure on high speed video. When played back at a slower speed, it was plain that the failure started at the locking notch on the cylinder, then almost like a zipper the crack propagated forward and back along the top of the cylinder.

Then the failure continued and the two webs between the adjacent chambers failed, literally folding and allowing the two adjacent chambers to rupture. But it all started at the locking slot, because the metal is the thinnest there.

I have a 19th Century Merwin Hulbert revolver that another friend managed to blow up. Here is a photo of it after the deed was done.





Here are a couple of views of the ruined cylinder.





Just as in my other friend's high speed video, the rupture started at the thin section under the locking slot. Notice that the web between chambers did not fail, but there was some folding going on at the two locking slots adjacent to the one that blew up. Much more force, and those chambers would have ruptured too.




Don't worry, my friend is an expert machinist and gunsmith, and he made a new cylinder to replace the blown up one, and welded a new top strap on.

Can you tell which one blew up?

-The reduction in cylinder weight achieved by fluting is significant, and an unfluted cylinder is much more likely to have timing issues, which would be exacerbated/guaranteed to happen "in rapid DA fire" (this myth is almost exclusively expressed with the "in rapid DA fire" qualifier so I'm including it here)

The difference in weight between a fluted cylinder and an unfluted cylinder for the same gun of the same caliber is not very significant. Peening of the locking slot takes place because if the cylinder is rotating rapidly it comes to an almost instantaneous stop when the bolt pops up into the locking slot. You know that old joke about the fall doesn't hurt, it's the quick stop at the end that hurts? Same thing. No matter if the cylinder is fluted or not, if it is rotating rapidly, the edge of the slot slams against the bolt and the deceleration is about as close as you can come to infinite. So some amount of peening caused by the metal 'flowing' slightly is to be expacted. By the way, a little bit of peening of the cylinder locking slot is absolutely normal on any double action revolver. Completely normal.

The arrow in this photo points to peening on the cylinder locking slots on the cylinder of a S&W K-38 made in 1949. Completely normal.



And here is some peening on the slots of a S&W Russian made in 1875. Completely normal.



Peening of this type in no way affects the timing of the gun, unless there is something else wrong with the lockwork. The bolt is designed so there is plenty of engagement in the slot, whether or not the surface of the slot has been slightly distorted.

By the way, rapid fire will not hurt the cylinder ratchet teeth at all. It may accelerate wear slightly, but there is plenty of surface area to absorb the friction of the parts rubbing against each other.



A long time ago, S&W used to insert a thin sliver of hardened steel at the edge of the locking slots. You can see it as the dark line at the edge of the locking slot on this old Lemon Squeezer. But they stopped doing this a long time ago when they started heat treating the entire cylinder for strength and wear resistance. Cheaper and easier than cutting a tiny slot and fastening a sliver of hardened steel in place.

-Fluted cylinders give you a physical reference you can index with your fingers, allowing you to reload while looking somewhere other than your cylinder. *This is the only one that I think is conclusively true.

Bingo! Absolutely true!

The simple fact is, on a well designed revolver, cutting flutes into the cylinder in no way weakens the cylinder. Check out the front and rear view of this 45 Colt 2nd Generation Single Action Army. The blast marks around the front of each chamber define the diameter of the forcing cone of the barrel. More important, you can see graphically that even with the flutes cut, there is still more metal remaining under the flutes than there is between the chambers. In no way does cutting these flutes make the cylinder weaker.







As somebody already said, back in percussion days most cylinders were unfluted. When cartridges came along, it became customary to flute the cylnder. And it added production steps to do so. But revolver manufacturers figured out well over 100 years ago how to flute a cylinder and still not weaken it.

 

[sequins]

Thank you for the post Driftwood Johnson, you pretty much nailed the door shut on some of my doubts. I'm glad I can continue to pursue fluted or unfluted based on aesthetic preference!

 

[BaltimoreBoy]

I don't claim to know an answer to the strength question.

However, I observe that

Ruger does not sell new model Blackhawks in 44 Mag - except for the Bisley hunter which has an unfluted cylinder.

Other than that, if you want a 44 Mag in a single action it looks like you have to get the Super Blackhawk.

I had assumed that this implied greater strength for the unfluted version - but perhaps there are other differences between the Bisley and regular New Blackhawk.

 

[CraigC]

Here's a 50th anniversary .44Mag Blackhawk from 2006. And the 5½" Supers are also fluted. The flutes were added with the debut of the Super Blackhawk in 1959 for the additional weight.

 

[SlowFuse]

Driftwood, the top one blew.

Very informative input, I like the looks of un-fluted cylinders.

 

[BobWright]

About a hundred years ago, I was shooting my Ruger .45 Colt "Super" Blackhawk on the range. After loading the revolver, I was sort of cradling it in my left hand. I slowly slid my shooting hand onto the grip and began to raise and cock the gun in one svelt, smooth move lining up on the target.

I was suddenly aware of sharp pain in my left hand at the base of my thumb. A little fold of skin had been impressed into the cylinder flute, and the rotating cylinder pinched it between the cylinder flute and topstrap of the gun.

You can bet I never did that again!

Other than that, no difference in fluted and non-fluted cylinders.

This the .45 Colt "Super" Blackhawk of which I speak:



Bob Wright

 

[Jim K]

The only real reasons for flutes are 1) weight reduction and 2) appearance. 1) is not very significant and 2) is in they eye of the beholder. Still, I prefer that look, just for tradition, I guess.

Jim

 

[CraigC]

But unfluted cylinders were tradition before fluted cylinders became tradition.

 

[pintler]

I'm not enough of a connoisseur to tell the difference myself, but I'll pass on a tidbit from a pretty good PPC shooter FWIW: he said they preferred to build PPC guns on 38's instead of 357's, not only because of cleaning issues when shooting 38's in 357 chambers, but because the 357 chambers were longer[1] and therefore heavier, and since when shooting double action the energy to accelerate the cylinder comes from your trigger finger, minimizing the energy needed is a good thing. It's going to be a small effect, but the physics is right, and fluting ought to have the same effect.

Like I say, my trigger finger can't tell the difference, but then box wine tastes as good as any to me, too


[1]I never measured myself

 

[CraigC]

I imagine that when you reach the upper levels of competition, every little detail counts for something.

 

[Driftwood Johnson]

Ruger does not sell new model Blackhawks in 44 Mag - except for the Bisley hunter which has an unfluted cylinder.

Other than that, if you want a 44 Mag in a single action it looks like you have to get the Super Blackhawk.

I had assumed that this implied greater strength for the unfluted version - but perhaps there are other differences between the Bisley and regular New Blackhawk.

Howdy Again

Flat Top Three Screw 44 Mag Blackhawk with fluted cylinder.



And the 44 Mag 'original model' Vaquero had a fluted cylinder too.

Look at my photo of the front of the 45 Colt SAA cylinder and you can see that a fluted cylinder is not going to be any weaker than an unfluted cylinder.

************


Yes, the upper MH is the one that blew up. You can see a slight bit of irregularity in the joint of the top strap to the frame.

 

[rcmodel]

As Driftwood Johnson correctly pointed out.

On a six-shot cylinder the locking bolt cuts are by far the thinnest section of the cylinder, and the point a failure started.

5-shot cylinders are stronger, because the bolt cuts are between the flutes, in the thickest part of the web between chambers,

IMO: An unfluted cylinder adds no strength at all, because that isn't where cylinders fail.

rc

 

[CraigC]

Prezactly!

 

[Buckeyeborn]

You need smarter buddies