Why the old S&W top break revolvers could handle Black Powder

[Driftwood Johnson, SASS #38283]

Howdy

 

I posted this over at CAS City a few months ago. With the relatively frequent questions concerning Schofields and Black Powder, here are a few photos that show why the 19th Century Smith and Wesson Top Break revolvers could handle Black Powder very well, while the modern reproductions made by Uberti, and even the recent Schofield made by S&W do so poorly with Black Powder.

 

These photos are of my New Model Number Three, which left the S&W factory in 1882. Although not identical to a Schofield, it is similar enough that it is useful for this discussion. If you are at all familiar with the Beretta Laramie, that is a pretty reasonable reproduction of the S&W New Model #3.

 

Here are two photos of the barrel/cylinder gap area on my New Model #3, from two slightly different angles. Notice how much space there is between the front of the cylinder and the frame. Notice how the barrel/cylinder gap is offset from the front of the gas collar.

 

Photo 01

 

 

Photo 02

 

 

Next is a closeup of the same area on an Uberti Schofield. Notice how much less space there is in front of the cylinder. Notice how the barrel/cylinder gap is almost in the same plane as the front of the gas collar.

 

Uberti Schofield Closeup

 

 

The next photo shows the detail of the gas collar milled onto the end of the cylinder. The gas collar stands about .165 proud of the face of the cylinder. The front face of the gas collar is what rides against the barrel frame. When the cylinder is assembled to the frame, the gas collar surrounds the arbor. The spring loaded rod with the hole through it is the extractor rod which rides inside the arbor.

 

 

Cylinder Detail

 

The last photo shows the relationship of the cylinder to the arbor it spins around. The arbor has helical grooves milled around it very similar to the grooves on a Colt style C&B revolver. These grooves provide a place for fouling to build up without causing the cylinder to bind as it rotates.

 

 

Cylinder and Arbor

 

When the gun is fired, the first line of defense against the cylinder binding is the fact that most of the fouling blasted out of the barrel/cylinder gap is deflected away from the arbor by the gas collar. Remember, the opening to the arbor is .165 away from the plane of the barrel cylinder gap. The next line of defense is the helical groove cut around the arbor, providing clearance for any fouling that manages to get by the gas collar. My New Model #3 is chambered for 44 Russian. With a Big Lube bullet carrying plenty of SPG bullet lube, the amount of fouling that gets past the gas collar is miniscule. Not enough to cause any binding at all after a six stage match, and most of it winds up in the helical groove. I haven't had a chance to use it for a bigger match yet, but I do not anticipate any problems. (Knock on wood)

 

When Uberti designed their version of the Schofield, they chose to chamber it for 45 Colt and 44-40. This required a longer cylinder to accommodate the longer rounds than the original gun had for the shorter Schofield rounds. Rather than stretch the frame, to keep the gas collar relationship the same, Uberti instead chose to keep the frame the same length and shorten up on the distance allowed for the gas collar. To be fair, I have recently read that 45 Schofield brass was not being produced at the time Uberti designed their gun. So Uberti designed it for the longer 45 Colt and 44-40 rounds. I have also read that it took S&W about three versions to get the gas collar design to work well with Black Powder back in the 1870s. So let's not be too hard on Uberti.

 

S&W on the other hand chose to chamber their 2000 version of the Schofield for the original 45 Schofield cartridge. I can only speculate that they messed with the very successful old gas collar design because they did not anticipate the gun would be used with Black Powder.

[Go West]

I like your posts as a rule and now I see what the gas ring is about. I have two Uberti top breaks, but I shoot smokeless because of the gag factor. My lungs are not what they used to be.

[Adirondack Jack, SASS #53440]

Now if ya pack that arbor on yer original S&W with bore butter (like some do on C&B Colts) ya ought to be able to run it all day. Too bad the repros weren't done like the originals.

[Doc McGee, SASS #51213]

What your are saying and picturing makes sense. Thigs are mighty close together on the Uberti.

 

Not to upset anyone's apple cart, but why then do OMV Rugers and Uberti Colt clones work so well with BP? Is it because there is more open space between the cylinder and frame? Ideas?

 

Doc McGee

[Smithy]

Not to upset anyone's apple cart, but why then do OMV Rugers and Uberti Colt clones work so well with BP? Is it because there is more open space between the cylinder and frame? Ideas?

 

Doc McGee

 

Not just OMV's but NMV's as well and the Colt clones are all built with a substantial "gas collar" on the muzzle side of the cylinder. Whether it be a one piece affair like the Ruger's or as sometimes found on the Colts, two pieces; the cylinder and separate gas collar, they still provide the same function in either example. This part of the design is still a hold over from the black powder days even though now built on an essentially smokeless gun. The trouble with the newer reproductions of S&W designs (top breaks, Russian, etc.) is that they went from the short Schofield round to 45 LC and did not lengthen the frame. To get the extra length that was needed they produced a longer cylinder and chopped off the gas collar. With no or relatively no gas collar to speak of, all the fouling goes straight onto the cylinder pin, is not deflected at all and pretty much binds things up right off the get go. Other readers please correct me on this if I don't have things straight here, but I think I've captured the essence of what's going on. Smithy.

[Driftwood Johnson, SASS #38283]

Not to upset anyone's apple cart, but why then do OMV Rugers and Uberti Colt clones work so well with BP? Is it because there is more open space between the cylinder and frame? Ideas?

 

Howdy

 

Add to your list the Single Action Army, that Uberti copied to make their reproductions.

 

Yes, it is the same reason, because the bushing on the front of the cylinder is so long. Not quite the same system, those guns do not have a large diameter arbor with clearance cuts on it, they all have small diameter pins, around 1/4" in diameter.

 

But the bushings on the front of the cylinders are long enough that the barrel/cylinder gap is not in the same plane as the spot where the pin emerges from the cylinder. When the gun fires, fouling blasted out of the barrel/cylinder gap is deflected away from the cylinder pin, so very little fouling manages to work its way into the hole where the cylinder pivots on its pin.

 

Here are a couple of photos of cylinders. Left to right in the first photo the cylinders are from an Uberti Cattleman, a stainless 'original model' Vaquero, and a 2nd Generation Colt. Notice the prominent bushings. The Ruger bushing extends .125 beyond the cylinder face, the Colt bushing extends .075 beyond the cylinder face, and the Uberti bushing extends .070. When powder fouling blasts out of the barrel cylinder gap it pretty much blasts out in the shape of a disk. It spreads out a little bit, but not so much that a prominent bushing on the front of the cylinder cannot deflect it away from cylinder pin.

 

cylinders

 

Now I just know that somebody is going to mention the fact that Colts and Ubertis have a separate, removable bushing that also contributes to their being able to digest Black Powder. Here is a photo of the bushings removed from their respective cylinders, the Uberti on the left and the Colt on the right.

 

bushings

 

Some may think the removable bushing helps with BP compatibility by offering a second bearing surface. My own personal experience is to the contrary. I can shoot my Rugers just as well as my Colts, for a ten stage two day match, with absolutely no cleaning or wiping down of anything. The Rugers perform just as well as the Colts. It is that big built in bushing up front that makes it possible, deflecting the fouling away from the cylinder pin. That and the fact that my bullets have tons of Black Powder compatible bullet lube on them.

 

The opposite end of the extreme is the Remington 1858 New Model Army cap & ball revolvers. These have no raised bushing on the front of the cylinder at all, and a narrow cylinder pin, around 1/4" in diameter. These revolvers are notorious for binding up quickly when shot with Black Powder. Both in the original C&B configuration or when shot with conversion cylinders. Here is a photo of two of my 1858 cylinders, a conversion cylinder made by R&D on the left and a C&B cylinder on the right. Notice the flat front of both cylinders and how small the cylinder pin hole is. When I shoot my Remmies with their conversion cylinders I have to stop and wipe off the front face of the cylinder with a damp cloth and wipe off the cylinder pin after every cylinder full or they will start to bind up on me. Even though I am using Big Lube bullets with tons of SPG lube on them. Because there is nothing to shield the pins from the BP fouling, it gets blasted into the pin hole and quickly binds up the gun.

 

Remington Cylinders

 

 

Here is a close up of the barrel/cylinder gap area on one of my Remmies with a R&D conversion cylinder in place. As you can see, there is no separation at all of the gap from the front of the cylinder. Nothing to keep fouling from being blasted directly onto the pin.

 

Remington 1858 Closeup

 

 

When Remington built their 1875 cartridge revolvers they did add a bushing to the front of the cylinder. But it is not very big. Current Uberti replicas of the 1875 Remington have a bushing that only stands about .035 proud of the cylinder face. They tend to shoot better with Black Powder than the 1858 model did, but they tend to bind up more quickly than a Colt, even with Big Lube bullets and plenty of lube.

 

These numbers start to give us some idea of how big a bushing is needed to deflect fouling away from the cylinder pin. The Ruger and Colt bushings at .125 and .075 respectively work well. The Remington bushing at .035 does not work as well. The lack of any bushing at all with the 1858 Remington makes it a dismal performer with Black Powder.

 

Now let's step back a bit. Raised bushings or collars were not the only way to deal with Black Powder fouling blasted out of the cylinder. Colt Cap & Ball revolvers had flat fronts on their cylinders too. They had no raised bushing of any sort. But Colt had a different idea. Colt Cap & Ball cylinders had a large diameter arbor the cylinder rotated on, not a pin. And the arbor had a helical groove running around it to provide a place for fouling to build up without binding the cylinder. Here is a photo of a Pietta replica of the 1860 Army Colt compared to The 1858 Remington design. Notice the large diameter of the Colt arbor and the helical grooves. Notice how much bigger the cylinder pivot hole is than the hole in the Remington cylinder. The combination of a large diameter arbor with clearance cuts on it meant that the fouling that was inevitably blasted onto the arbor, could be captured in the clearance grooves and not bind up the cylinder.

 

 

Arbors and Pins

 

 

By the way, ignore the grooves cut into the Remington pin, those are my own feeble attempt to cut reliefs into the pin and create spaces to hold extra Bore Butter. It does not work very well. In comparison I can shoot the 1860 Colts for an entire match and not need to wipe down or lube anything.

 

 

Getting back to the original subject, what Smith and Wesson did was take the best of both worlds. They used a large diameter arbor with clearance cuts on it, and they used a prominent gas collar to shield the arbor from the fouling blasted out of the barrel/cylinder gap. But it did take some development. It took S&W three tries to get it right, during 44 American and 44 Russian production. But once they learned the lesson of a good gas collar, S&W stuck with the idea. Eventually both the New Model Number Three and it's brother the 44 Double Action top break model were chambered for both 38-40 and 44-40. These cartridges would not fit into the shorter cylinders designed for the 44 Russian and 45 Schofield cartridges, so S&W lengthened the cylinder by about 1/8" to accommodate the longer cartridges. But they also lengthened the frame by the same 1/8", so the gas collar did not have to be compromised.

 

Smith used the same idea of a gas collar on their 32 and 38 caliber top breaks too. I have a 32 lemon squeezer and a couple of 38 top breaks. They all have a prominent gas collar on the front of the cylinder. Interestingly enough, they all lack the helical clearance cuts.

 

While I still have the floor, if I'm not being to blabby already, I'm sure somebody is going to eventually mention the idea of opening up the barrel/cylinder gap to allow more clearance for fouling to build up. I can categorically state that as long as plenty of Black Powder compatible bullet lube is used, there is no need to open up the barrel/cylinder gap. In addition to my New Model Number Three, I shoot Black Powder in Colts, clones and Rugers. All of them have their original stock cylinder gaps, ranging from .005 to .008. None of them have been altered. They all can shoot an entire match, with no additional cleaning or wiping, with their factory gaps.

[Captain Woodrow Cahill, SASS # 54363]

Very informative article Driftwood. Thanx for posting.

 

Delving into the realm of theoretical machining, I would like to pose two questions.

Regarding the grease grooves on the arbor pin, do you think a series of grooves about .015" deep would help? I've noticed when I grease and re-assemble my Vaqueros that much of it gets swept off the pin. I'm thinking that grooves would hold more of the grease captive and present a series of grease gaskets (for want of a better term) to keep fouling from creeping down the pin.

 

Secondly, the bushing on the face of the cylinder is basically a little cylinder itself. Do you think tapering it down to more of a cone shape would further help to direct fouling away from the cylinder face and pin? I'm thinking that providing it with more direction it would tend to blow forward.

 

I agree with your assertion (posted here and previously) that a wide gap is unnecessary and probably exacerbates cylinder face fouling. A wide gap allows for more fouling and gases to blast out instead of being sent downbore. And then there's the issue of gas cutting the topstrap too.

[Driftwood Johnson, SASS #38283]

Howdy Cap

 

I suppose one could try machining some grooves on the cylinder pin of a Colt or Ruger. My personal experience has been that since the bushing is so effective at keeping fouling away in the first place, it is not necessary. If you take a close look at the photo comparing the Colt and Remington C&B revolvers, you will see I cut some crude grooves into the cylinder pin on the Remington. I did not have access to a lathe, so I chucked the pin in my drill press and went at it with a file while it was spinning. That's why the grooves look so crude. I don't have the gun in front of me right now, so I cannot say how deep they are. My guess is around .030 deep or so. The idea was to load up the grooves with bore butter to help keep the cylinder rolling better. It did not help much, I still have to wipe the cylinder face every time I reload the gun. The design of the Remington and the R&D cylinder is such that the cylinder has to be removed every time it is loaded anyway, so wiping the cylinder and pin every time is not a big deal. The other thing to consider is these pins are relatively narrow, only about .250. So one is not going to want to cut too much material away for fear of weakening the pin.

 

Your question about shaping the bushing is interesting though. If I understand you correctly, you do not want to direct the fouling forward. That will send it towards the cylinder pin. If anything, you want to direct it straight out. Take another look at the photos of the Ruger, Uberti, and Colt cylinders. Notice the flute running around the head of the Colt bushing? Uberti has imitated it, but the shape is more developed on the Colt pin. I was visiting Happy Trails once a few years ago and he was in the process of cutting a similar rounded flute around the bushing on a Ruger. Hap was of the opinion that this relief cut helps direct the fouling outwards and away from the cylinder pin, heightening the effectiveness of the bushing. I shoot a lot more Black Powder than Hap does, but I have a great deal of respect for his opinions relating to gun design. He has forgotten more than I will ever know. As I said earlier, my Rugers deflect enough fouling away from base pin that I can shoot them all day with Black Powder, but I'll bet in a marginal situation a little directing of the fouling would be of some help.

 

As a matter of fact I was reading another of Hap's old customers the other day saying that Hap fitted a collar to his 1875 Remington. I think it was a 1875 Remington. Hap made a new collar, taller that the stock .035 tall collar and pressed it into the cylinder. He then cleared out enough material from the frame to clear the new bushing. I believe Hap also put a groove around the new bushing, to help direct the flow of the fouling.

 

If you study the photos of the shape of the gas collar on my New Model Number Three, you will see the collar is not a simple cylinder, but has some taper to one end. However, I suspect this is simply to make enough clearance around the barrel.

[Flint 976]

I have made gas rings for the Remington C&B. I requires machining away some of the frame below the barrel. Note that I also fluted it.

 

It also has the effect of setting headspace, not as critical in a C&B, but which is a necessity in a cartridge gun.

 

http://i13.photobucket.com/albums/a293/rcflint/cylindergasring.jpg

 

http://i13.photobucket.com/albums/a293/rcflint/gasringinframe.jpg

[Gunner Gatlin, SASS 10274L]

I have made gas rings for the Remington C&B. I requires machining away some of the frame below the barrel. Note that I also fluted it.

 

It also has the effect of setting headspace, not as critical in a C&B, but which is a necessity in a cartridge gun.

 

http://i13.photobuck...ndergasring.jpg

 

http://i13.photobuck...ringinframe.jpg

 

That's great!!!!

 

GG ~

[Cypress Sam, SASS #10915]

Driftwood, Thanks for an excellent study of gas rings on the various guns we use for CAS. I, for one, would like to see you write up some of your evaluations for the Chronicle. Much more interesting than some of the stuff that appears now!

 

Flint, Interesting modification for the '58 Remington. Is that gun converted for cartridge? It looks like the loading lever has been replaced with a latch for the base pin.

[Rex M Rugers #6621]

Great thread!!! Worth about a hundred "dead horse" threads. And I must say , Driftwood , you have a lot of nice toys. Really like that Smith & Wesson.

Keep 'em smokin , Rex

[Flint 976]

The gun is not converted to cartridge, but the barrel is too short for a loading lever (4-1/2"). The retainer clip is one I made.

 

http://i13.photobucket.com/albums/a293/rcflint/sslatchassy.jpg

 

http://i13.photobucket.com/albums/a293/rcflint/rammerplugandlatchdetail.jpg

[Captain Woodrow Cahill, SASS # 54363]

On reading your post and taking a second look at the pics, I understand what you mean Driftwood.

Instead of trying to direct the fouling gases forward away from the face and pin, having the ring cut around the bushing actually channels the blast around the bushing and the pin. Genius!

 

I checked my Rugers, and the bushing only stands .065" proud of the cylinder face. Not much room there for cutting a blast channel.

[Driftwood Johnson, SASS #38283]

Howdy Again Cap

 

What type of Rugers do you have? The bushing on my 'original model' stands .125 proud of the cylinder. The bushing on Mrs Johnson's New Vaqueros stands .090 proud. If you look closely at the way Colt did it, the larger diameter 'head' of the bushing sits partially in a counterbore in the cylinder. When seated in the counterbore, the bushing extends .075 past the cylinder face, but part of the relief cut is buried in the cylinder. The Uberti version has just about all of the relief cut exposed above the face of the cylinder. Frankly, I doubt if Uberti was thinking of Black Powder shooting when they prototyped their version. They probably just wanted to make the bushing look like a Colt bushing.

 

We are probably talking diminishing returns here. If your bushing only stands .065 proud, you could probably squeeze in a groove with a diameter of around .047 or so, but the effect might not be much at that point.

 

Just guessing of course, I have absolutely no data to back it up.