Grantville Gazette - Volume V (40 page)

All of these single-shot designs confer a major military advantage: they allow effective reloading from the prone position. The troops no longer have to expose themselves to enemy fire by standing upright to reload the SRG from the muzzle. This preserves the lives of veterans and allows recruits a better chance of becoming veterans in the first place. But all of the designs except the Trapdoor have the disadvantage of requiring entirely new tooling to produce, thus delaying their introduction and keeping the troops exposed in the interim.

Still others of us want to skip single shots and go straight to magazine rifles. But the question arises, which magazine rifle: lever action, bolt action or something else? The familiar Winchester lever action is well known and common in the area. Mauser and Lee style actions are the most common bolt-action hunting rifles. Add in the semi-auto SKS and you have the typical hunting rifles of the area. All of these magazine rifles give the prone reloading advantage, but they all require entirely new tooling (and even more of it than the single-shots), so they would increase the time the troops are exposed.

First we will look at the Sharps design. The Sharps designed by Christian Sharps in the 1840s is what is called a sliding block rifle. The breechblock, that part that closes the firing chamber, slides down to open the chamber when the operating lever is moved. Since the breechblock is almost totally enclosed by metal it is a very strong design.

The early Sharps design used a linen or paper cartridge and percussion cap. This cartridge was just a bullet and powder charge wrapped in paper or linen. The paper or linen would usually be impregnated with potassium nitrate for easy ignition and thorough burning. The ignition or priming was provided by a percussion cap on an external nipple, much like any other cap lock rifle of the period. While some early Sharps used a disc primer, where the primer was thrown forward by the movement of the hammer, making the rifle self priming, most of the reproduction rifles do not. The disc primer system was found to be too "fiddly" for hard field usage. Later Sharps used metallic cartridges and were still in production at the time of the Ring of Fire (RoF). In this latter design, the external nipple is replaced by a firing pin, which is driven by the hammer to strike the primer of the cartridge.

The advantages of the Sharps design for the residents of Grantville would be its strength, and the fact that it is a percussion design that could be easily converted to a cartridge rifle. The major disadvantage is it requires very tight tolerances in the machining of the breechblock. It also doesn't allow the user to stay as low while reloading as some of the other designs do.

Another design that has been discussed is the Hall. The Hall is what is called a tipping block action. In this case the breechblock forms the chamber of the rifle and it tips up for loading. In the case of the Hall, the block tips up in the front and is loaded with a paper cartridge, much like that of the Sharps, then the block is lowered to align with the barrel and the weapon is primed, either with a cap or as in earlier versions by priming the pan. The Hall was designed in the 1830s and manufactured at first as a flintlock and later as a caplock rifle.

The advantages of the Hall are its ease of manufacture and the fact it could be manufactured in both flint and percussion versions.

Its disadvantages are that it is a relatively weak design and is not easily converted to use a metallic cartridge.

The third design we discussed was the tip-down. In the tip down, the entire barrel and breech tips out of the action to expose the breech for loading. The most common weapon of this type today is the single barrel shotgun, still about the cheapest hunting arm available. But there are rifles based on this design. The H&R Handi-rifle comes to mind as do a number of survival type weapons. Indeed the Frank Wesson rifle of the 1870s may be thought of as the father of this design. But Wesson based his rifle on an even older design called the Maynard. The Maynard is an oddity in that early models used a metallic cartridge, but had an external nipple for a percussion cap. Later models used a standard style metallic cartridge.

The advantages of this design are its ease of manufacture and the small number of parts. Another advantage is it could be manufactured as a mixed rifle, like the Maynard, using a metallic cartridge and a percussion cap. Its major disadvantages are it would be hard to strengthen to use a bayonet and it doesn't allow the soldier to stay as low while reloading as some of the alternatives do. Also, while the Maynards had a reputation for accuracy, it is not the most accurate of designs.

A fourth design is the trapdoor Springfield. This design was developed by the United States after the American Civil War to get a cartridge rifle into service while taking maximum advantage of existing stocks of surplus percussion rifled muskets and the existing tooling that had made them. Existing rifle muskets were converted by replacing the breech portion of the barrel with a hinged breechblock that swung up for loading like a trap door, hence the name. The cartridge was fired by a firing pin that extended through the breechblock and was struck by a hammer only slightly modified from that of the rifle musket. New rifles using this system were produced up through the mid 1890s using much of the same tooling that had been used through the Civil War. Only the breechblock itself and the barrels (for later models built around the more efficient .45-70 cartridge) were significantly different from the parts of the previous rifle muskets.

The advantages of this design for the USE are its use of most of the existing SRG tooling and the ability to convert existing SRGs fairly quickly and easily. The disadvantages are two:

1) The action is weaker than the Sharps or rolling block, and thus would be less effective if later converted to smokeless powder.

2) The easiest cartridges to convert to (.577 caliber with existing SRG barrels or .50-70 with sleeved SRG barrels) are not the most efficient black powder cartridges for longer ranges.

The final design of a single shot rifle we will discuss in this report is the Remington rolling block. As its name implies, the breechblock in the Remington design rolls back in the action to expose the chamber. The block is hinged on a pin through the walls of the breech. This pin is slightly off center, and thus the breechblock pivots downward when it is opened. At first glance the Remington does not look like a strong design, but it is. The breechblock is locked in a closed position by both the nose of the hammer, which fits into a slight recess in the breechblock, and by an extension of the lower part of the hammer which extends under the block.

The advantages of the rolling block design are its strength and its simplicity of manufacture. Its major disadvantage is that it requires a metallic cartridge, because there is no positive sealing of the breech.

Now we want to look at repeater designs. Repeating rifles are another force multiplier, like the organ gun discussed in our prior article ("How to Make a Machine Gun in 1634 with Available Technology; Alternate Views,"
Grantville Gazette,
Vol.4). One squad with repeating rifles will handily out-gun two or three squads armed with single-shot rifles. This is the type of weapon that the USE needs to produce a smaller, better army.

The basic lever-action rifle needs no introduction. It has been seen in movies and television for years. Also it is very common as a deer rifle in the area of Grantville. Basically it works by moving the lever under the action. This opens the breech, ejects the spent cartridge from the chamber, pulls a new cartridge from the magazine, and chambers it, making the rifle ready for firing. Its speed and ease of operation has been proven by American hunters for well over one hundred and fifty years. But the lever action has its drawbacks. One is that it has many parts that are fitted under very close tolerances. If it has a tubular magazine, it is restricted to round-nose bullets. Round-nose bullets are not as accurate as pointed ones and lose velocity more rapidly. It also cannot be used as well from the prone position as the other repeater designs discussed below.

Bolt action rifles are another possible repeater. The Mauser-based designs are quite common and Lee-Enfields are common as surplus rifles converted to sporting use. The major difference between the two is the location of the locking lugs. The locking lugs are those projections on the bolt that hold it against the recoiling cartridge case when firing the rifle. Both are very strong actions and both were designed in the time when black powder cartridges were common. As a side note the American Springfield of 1903 is a Mauser-based rifle. They have a lot of advantages. They are strong, accurate, and easy to design to be fitted with a bayonet. And as the later versions of both designs prove (SMLE #4, Springfield 03-A3, and VG-1 Mauser), they can be produced with a minimum number of parts in small shops.

Another possibility is the SKS. The modern SKS uses a bit of high-pressure gas from the firing of the cartridge to move the bolt back, extracting the fired cartridge; and has a large spring that returns the bolt forward, picking up the new cartridge from its ten-shot magazine on the way. Black powder would foul such a gas system almost immediately, and cleaner-burning smokeless powder won't be available until very pure acids and reagents are available—probably at least ten years from 1632. But if the gas system was eliminated, a human hand could cycle the bolt easily enough.

A black powder SKS could later be adapted for smokeless powder and semi-automatic operation—not that many of the rifles would be so adapted, but the tooling, design, and machinery would not have to be replaced when better cartridge design and propellant availability would make a black powder straight pull rifle obsolete.

The SKS uses the classic 7.62x39 cartridge. This relatively small cartridge has plenty of power with the higher-energy smokeless power, but would be underpowered with black powder, so a new cartridge would be needed. It should be about .38-45 caliber, and long enough to produce sufficient velocities with black powder. A straight case about two inches long would be ideal. The base would need to be at least semi-rimless because a rimless case starts becoming harder to chamber as black powder fouling builds up, and a manual SKS action doesn't have the camming action that allows a turn-bolt to overcome this resistance. A semi-rimless case could still allow easy feeding while head spacing on the rim rather than the shoulder.

A shortened version of this round could also be used in pistols.

The major drawback of any magazine rifle we can think of for the 163x timeframe is that all would require very uniform cartridges. A few hundredths of an inch short or long could jam the gun.

Which brings us to metallic cartridges. 

The modern metallic cartridge looks simple, but it really performs a complex job.

A cartridge has three functions:

1) It acts as a carrier of the powder, primer and shot, keeping them together and protected from the elements.

2) It acts as a seal for the firing chamber.

3) It acts as a heat sink and carries some of the heat of the burning powder away from the firearm.

The basic design is indeed simple: a metal tube closed on one end, with a bullet on the other. The closed end is called the base of the cartridge and in most designs is not really closed but has a pocket drilled in it. This pocket is called the primer pocket and, as you might guess, is where the primer goes. The primer pocket is connected to the interior of the cartridge by either a single hole or a series of smaller holes. These holes, called flash holes, allow the fire from the primer to reach the powder charge in the cartridge. When the flame of the primer reaches the powder charge the charge ignites and the gasses released push the bullet down the barrel and toward the target.

A loaded round consists of the cartridge case, the bullet, the powder charge and the primer. Sometimes if the case is large and the powder charge is small, there may also be a filler to fill the empty space inside the case.

Let's look at the base of the case. If the case has a rim or lip around the base it is called a rimmed case, such as the .30-30, .38 Special and .45 Long Colt. If the case has no rim but instead a groove cut around the base it is called rimless, such as the .223, .308 and .45ACP. If it has a very small rim and a groove it is called semi-rimmed. The rim and the groove are both used to extract or pull the cartridge out of the firearm. As you might expect, the piece of the rifle that extracts the cartridge is called the extractor. There are two types of cartridge which it is hoped the citizens of Grantville will avoid, but they probably won't. These are the rebated, where the base is smaller than the body of the cartridge: this is found in the modern .41 Action Express. And the belted, where a belt, or extra thick ring is formed around the cartridge just in front of the extracting groove. Belted cartridges are found today in a number of high-powered rifle cartridges such as the .375 Holland and Holland, the .458 Winchester and the .460 Weatherby.

Rimmed cases work best in single shot designs and rimless cases work best in magazine designs. It is of course possible to make a rimless cartridge work in a single shot or a rimmed case work in a magazine design, but it takes a little extra design work. The rim around the base of a rimmed cartridge stops the cartridge from going too far into the chamber of the rifle and positions the base or head of the cartridge where it can be supported by the bolt and struck by the firing pin. This positioning is called head space. Rimless cartridges head space upon their shoulders, that portion of the front of the case where it narrows down to the neck that accepts and holds the bullet. It is likely that black powder fouling will give trouble in this area. This fouling would prevent chambering a new cartridge very quickly. This is even more of a consideration for machine gun use.

Now we will move toward the other end of the case. The body of the case will, in most cartridges, have a slight taper to aid extraction. The front of the case is the next area we need to look at. If the case is relatively the same size from the base to the bullet, the case is called a straight case. We know it has a very slight taper but it is still called straight. If, on the other hand, the bullet is much smaller than the case and the case is squeezed down to hold it, this is called a bottlenecked case, or necked case. Examples of a straight case are the .45-70, .30 carbine and most pistol cases. Examples of necked cases are the .30-06, 8mm Mauser and most modern rifle cartridges. Necked cases allow greater powder charges without making the cartridge case overly long and fragile, and aid in "internal ballistics"—how well the powder burns inside the cartridge case.