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S&W Antiques S&W Lever Action Pistols, Tip-Up Revolvers, ALL Top-Break Revolvers, and ALL Single Shots


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  #1  
Old 09-17-2007, 12:38 PM
Win38-55 Win38-55 is offline
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Different powders burn at different rates and, thus, produce different peak pressures and burning curves. Smokeless powders slower than Blue Dot or 2400 will produce lower peak pressures than black powder for the same velocity, all other things being equal. What this means, contrary to many gun writers, is that certain smokeless powders are actually safer to use in black powder guns than black powder is. Powders faster than Blue Dot/2400 produce a higher pressure spike than black powder, with the Blue Dot/2400 producing a peak pressure similar to black powder, for the same velocity and all othe things being equal. For this reason, if a fellow is going to use Unique in an old pistol, he needs to understand that the peak pressure of Unique is much higher than black powder for the same velocity and all other things being equal. Therefore, he needs to decrease the muzzle velocity accordingly. Trail Boss is even worse, being a very fast powder with a burning speed in the neighbourhood of Bullseye.

For the 44 Russian, I use 12.5 grains of Accurate 5744 under a 256 grain cast Elmer Keith bullet for and average velocity of 780 fps. Recently, I was shooting at a target tacked to a hard, dry cedar tree 25 yards away that was about 7" thick. This load was putting the cast bullets right through the tree. When I first started using this load in my S&W New Model #3, I began to measure the distance from the forcing cone to the back of the frame to the nearest half thou. I eventually quit because there was no measureable change after a few hundred rounds.

In general, the pistol load charts today seem to go by the fast-powder-in-tiny-amounts strategy. You don't want this for antique pistols. I go by the slow-powder-in-large-case-filling-amounts strategy, for low peak pressures.

Too high a pressure for the same velocity will blow your cylinder but not stretch the frame. A velocity higher than BP, even if the pressure is fine, may begin to stretch your frame. You must both keep the pressure at or below BP pressures by using powder slower than 2400 and you must also keep your bullet momentum at or below original specs. Bullet momentum = weight x velocity. You do need to Chrono your loads when you are developing them to know where you are.

Start with a slow powder like 5744 or IMR 4198. Load up a round with a very conservative amount of powder and chronograph the velocity. Then increase the powder amount until you either max out the case capacity, or reach original black powder velocities, whichever comes first. Some powders, like IMR 4198 may be too slow and you will max out the case capacity before you get near the original BP velocity. If this happens, you may have to go with a slightly faster powder like 5744. However, I never use a powder faster than 2400 in an antique pistol, just to be on the conservative side.
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Old 09-17-2007, 12:38 PM
Win38-55 Win38-55 is offline
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Different powders burn at different rates and, thus, produce different peak pressures and burning curves. Smokeless powders slower than Blue Dot or 2400 will produce lower peak pressures than black powder for the same velocity, all other things being equal. What this means, contrary to many gun writers, is that certain smokeless powders are actually safer to use in black powder guns than black powder is. Powders faster than Blue Dot/2400 produce a higher pressure spike than black powder, with the Blue Dot/2400 producing a peak pressure similar to black powder, for the same velocity and all othe things being equal. For this reason, if a fellow is going to use Unique in an old pistol, he needs to understand that the peak pressure of Unique is much higher than black powder for the same velocity and all other things being equal. Therefore, he needs to decrease the muzzle velocity accordingly. Trail Boss is even worse, being a very fast powder with a burning speed in the neighbourhood of Bullseye.

For the 44 Russian, I use 12.5 grains of Accurate 5744 under a 256 grain cast Elmer Keith bullet for and average velocity of 780 fps. Recently, I was shooting at a target tacked to a hard, dry cedar tree 25 yards away that was about 7" thick. This load was putting the cast bullets right through the tree. When I first started using this load in my S&W New Model #3, I began to measure the distance from the forcing cone to the back of the frame to the nearest half thou. I eventually quit because there was no measureable change after a few hundred rounds.

In general, the pistol load charts today seem to go by the fast-powder-in-tiny-amounts strategy. You don't want this for antique pistols. I go by the slow-powder-in-large-case-filling-amounts strategy, for low peak pressures.

Too high a pressure for the same velocity will blow your cylinder but not stretch the frame. A velocity higher than BP, even if the pressure is fine, may begin to stretch your frame. You must both keep the pressure at or below BP pressures by using powder slower than 2400 and you must also keep your bullet momentum at or below original specs. Bullet momentum = weight x velocity. You do need to Chrono your loads when you are developing them to know where you are.

Start with a slow powder like 5744 or IMR 4198. Load up a round with a very conservative amount of powder and chronograph the velocity. Then increase the powder amount until you either max out the case capacity, or reach original black powder velocities, whichever comes first. Some powders, like IMR 4198 may be too slow and you will max out the case capacity before you get near the original BP velocity. If this happens, you may have to go with a slightly faster powder like 5744. However, I never use a powder faster than 2400 in an antique pistol, just to be on the conservative side.
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Old 09-18-2007, 11:12 AM
Driftwood Johnson Driftwood Johnson is offline
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Howdy

A subject near and dear to my heart. Here is a comparison of two pressure curves that were sent to be by a gentleman who used to work as a technician in a ballistics lab. The two charts are for two different shotgun loads that achieve the same velocity with the same weight of shot. The Black Powder curve is from a 3 dram charge (82 grains) of FFg Black Powder. The Smokeless curve is from 18 grains of an unknown Smokeless Powder. This chart shows the typical relationship of a Smokeless charge and a BP charge propelling identical projectiles at the same velocity. The peak pressure of the Smokeless charge is higher, and the duration is of the peak is much shorter, creating the sharp spike. It is not just the peak pressure, it is also the sharp spike that can damage an older gun with older steel, shocking the steel more than the gentler curve of BP will. What you say may be true if one works with a specific powder, but I would be much more comfortable seeing the duration of the pressure spike, in addition to the peak pressure.

I shoot a great deal of Black Powder in cartridges, I go through about 20 pounds per year. For me it is just much simpler to shoot old guns with Black Powder than to risk an old gun with Smokeless. Colt did not factory guarantee the SAA for Smokeless powder until 1900. Until that time they were not confident the steel could withstand Smokeless pressures. I doubt if S&W had access to any better steel than Colt did.

I will continue to only shoot BP in old guns, it isn't nearly as much trouble as most people think.

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Old 09-18-2007, 12:14 PM
Win38-55 Win38-55 is offline
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The chart posted above is for a very fast, shotgun powder, which I would never touch with a 10-foot pole in an antique sixgun. My initial post rules out any smokeless powder faster than 2400, which rules out all shotgun smokeless powders (which tend to be very fast).

The smokeless powder used in that plot appears to be for a shotgun. Smokeless shotgun powder is a fast powder. For example, Herco, a common smokeless powder used for shotguns, has a Du Pont Index (DPI) of 393 and a Relative Quickness of RQ of 56.1. Compare that with 2400 which gives about the same pressure curve as Black Powder and is the fastest powder I would ever use in a black powder antique. 2400 has a DPI of 189 and an RQ of 27. What that means is that the peak pressure spike is about half that of smokeless shotgun powder Herco.

My initial post stated that I never use a smokeless powder faster than 2400, which rules out all smokeless shotgun powders. It also rules out pretty much all pistol powders except for the very slow ones. Since I hear of a lot of fellows using Unique in their antique pistols, I want to specifically say that Unique is ruled out as well, with its DPI of 431 and RQ of 61.6. Thank goodness a lot of fellows who use Unique do so at reduced velocity, but I still shudder.

Anyone who reloads must be clear on the difference between fast and slow powders and have access to a chart that ranks the smokeless powders according to burn speed. For starters, I would recommend studying this http://www.chuckhawks.com/powder_burning_speed.htm . Also, I would recommend Sherman Bell's article, 'Finding out for myself: Part X' in The Double Gun Journal, Autumn, 2005. In that article, Bell shows that slow smokeless powders generate lower pressure curves than black powder and are actually safer than black powder so far as antiques are concerned for the same velocity, same bullet, same case .

There are a lot of urban myths about using smokeless powder in old black powder guns. Those of us who are reloaders need to be able to help clear up these myths.

If I were to summarize the rules for using smokeless powder in black powder antiques, they would be as follows:

1. Never use a powder faster than 2400 (this rules out Unique by a long shot)
2. Never exceed the original black powder velocity with the original black powder bullet seated to the original black powder depth.
3. It is preferable to use a powder that is slower than 2400, such as 5744 or IMR 4198. That will keep the pressure spike and curve well below black powder pressures.

I use black powder only in more modern firearms but almost never in any of my antiques. I have shot thousands of rounds of smokeless powder in my antique S&W and black powder Winchesters. My reason; Although I am a fanatic about cleaning black powder residue out of every crevice and tiny pit, I can never be sure that the bottoms of the tiny pits that are in some of my barrels have been perfectly cleaned out. Over time, those pits are going to get larger if even a tiny trace of residue is left in them. Perhaps I am too cautious with my antiques, but I believe my slow, smokeless loads are much safer than black powder, and significantly reduce the risk of corrosion in tiny pits, or in the various recesses found in six-shooters.

Having said all this, I have nothing against those who want to shoot black powder in their antiques. I know that it is a lot more fun, with more smoke and boom than smokeless. I have to confess I much prefer shooting black powder so, on very special occassions, I do use black powder in my antiques, but those occassions got to be real special before I will do it.
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Old 09-18-2007, 12:36 PM
Driftwood Johnson Driftwood Johnson is offline
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Howdy again

I too have old Winchesters and Marlins that I shoot with Smokeless. These are 44-40 rifles. I keep the Smokeless loads light in the old guns. The actions of a Winchester '92 or a Marlin '94 are plenty strong enough to withstand those loads.

Regarding Black Powder fouling left in pits. My old rifles have pitted bores typical of guns their age. The rifling is still strong, but there are thousands of tiny pits. The main reason I use Smokeless in those old rifles with their pitted bores is because of all the extra elbow grease required to get the fouling out of the pits.

But Black Powder is no where near as corrosive as most shooters think. Part of the problem was the combination of Black Powder fouling with corrosive primers. Now that we no longer use corrosive primers, the BP fouling itself is no where near as corrosive as most shooters think.

Black Powder fouling is extremely dry. It corrodes a bore by wicking moisture out of the air and holding it in close contact with the metal. It is the water that causes the rust, not the fouling. But if you infuse BP fouling with oil it completely looses its ability to wick moisture out of the air. If you do the best job you can of removing the majority of the BP fouling, and then coat the bore with oil, the oil will prevent any remaining fouling from wicking any more moisture out of the air and you will not get any rust. I've been doing this for years. After cleaning the bore of one of my old rifles I soak a patch in Ballistol and twirl it down the bore, being sure to coat the bore well with the oil. Then I put the gun away. I get no rust. The BP fouling has been rendered harmless.

I do basically the same thing with a revolver that I have fired with Black Powder. After cleaning the bore, chambers, and all visible surfaces I work some Murphy's Mix down into the action through the hand window with a Q-Tip. Then I squirt some Ballistol down there for good measure. I only disassemble my BP guns once a year to clean out the black, oily guck. There is always plenty of black, oily guck. There is never any rust. The oily BP fouling was not able to wick any moisture out of the air and cause any rust.
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Old 09-18-2007, 06:09 PM
Win38-55 Win38-55 is offline
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Driftwood, that is helpful info. I probably worry too much about getting every last bit of black powder fowling out of my guns. Your point about coating the cleaned bore with oil is a good one. I also agree regarding the corrosive primers. I find that it is relatively common to find an old Winchester that came out in the early 1900's after the black powder era, to have a great bore except just in front of the chamber, where there is pitting caused by the corrisive primers used at that time.

I don't find it to be much of a problem to clean my rifles if I use black powder in them. The S&W New Model #3 and the Schofield seem to me to be a whole bigger problem, with the black powder residue also blowing out of the tiny gap between the cylinder and the forcing cone. The problem is getting every part of the cylinder and ejector assembly in the cylinder spiffy clean. Your method is helpful to me. Maybe I'm going to celebrate a little more often by using black powder in those pistols. They are much more impressive with black powder.
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bullseye, chronograph, colt, ejector, fouling, projectiles, russian, saa, schofield, sig arms, winchester

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