Loading and Shooting Black Powder Shotgun Cartridges
How many old shotguns hide in dark corners of gun safes? Most of these guns were made at the pinnacle of gun-making history. Some are still in use (with pride I hope) for sports shooting and bird hunting. If you are fortunate to own such an old shotgun, in good condition, spoil yourself and go shooting. It is satisfying to be able to use an old gun safely and effectively. One advantage of black powder is the reduction of recoil. Black powder causes a gentle acceleration of wad and shot without a significant reduction in muzzle velocity.
Another advantage of shooting black powder is the shot patterns, and in most cases, are more evenly spread. Shooting clay targets with a well-balanced black powder load will give you a distinct advantage over nitro ammunition. It is also one of the reasons why black powder cartridges are prohibited in most modern certain clay target shooting disciplines.
Too often nitro ammunition is used in black powder guns. Most mistakes are made through ignorance. Worst of all, 70mm (2¾”) nitro ammunition are fired in 65mm(2½”) chambers. Many black powder shotguns are declared unserviceable due to the lack of appropriate ammunition.
Armed with the right information, owners of breach loading black powder shotguns will be able to use their guns for the purpose they were meant. Generally, this information is based on reloading for a 12 Gauge with a 2½” chamber. These guns, usually with external hammers were quite common and were normally manufactured before or round about 1900. The information could also be adapted for other chamber lengths and calibers.
Have your gun Checked
Before attempting to shoot any old shotgun, it is of utmost importance to have the gun checked out by a competent gunsmith. And remember your local gun shop assistant may claim that he knows everything (with respect to some of them); you should find a gunsmith that has experience in repairing and evaluating old shotguns.
Once you are informed that your gun is safe to shoot, also ask the gunsmith to measure your chamber size and explain the proof marks to you. Almost all old shotguns with external hammers were originally designed to shoot black powder. This is especially true for guns with Damascus barrels.
Although some old shotguns do have nitro proof marks on the barrels, it doesn’t mean that your old gun’s action is able to withstand the pressure of nitro propellants. Pressure created by modern propellants could be double that of a black powder load.
Therefore, even if it has nitro proof marks, and especially if it has external hammers, rather use black powder rounds. A shotgun with Damascus barrel should only be used with black powder loads.
Chamber size
Most old British-made shotguns with external hammers do not have a 2¾” (70mm) chamber. Many British and colonial guns before 1900 were manufactured with 2½” chambers and even shorter 2¼” and 2” can be encountered.
Most worrying with this is that you will be able to chamber almost any loaded cartridges, irrespective of their length. This is where your problems start.
You will not be able to use the modern reloading equipment because of the required length of the cartridge and the type of wads to be used in conjunction with black powder. Knowing and understanding your shotgun’s chamber size is the first step to ensure that you do not damage yourself or your gun.
In diagram A, it clearly illustrates that any modern star crimped cartridge will fit any smaller chamber. A modern 70mm cartridge will also chamber into a 2” chamber, with possible disastrous results. The length of the cartridge only becomes apparent when the front of the cartridge is opened fully (i.e. fired)! If a 2¾” cartridge is shot in a 2½” chamber, the front of the cartridge cannot open fully, forming a bottleneck, pushing internal pressure dangerously high. When this happens, there is a restriction or “ bottle-neck in the front part of the chamber due to the opened case wall thickness restricting the shot and wad to pass into the barrel freely. There is not enough room for a dense felt wad to pass unrestricted due to the obstruction caused by the longer case. Take note: These additional strains placed on an antique barrel may reduce fingers, limbs or even shorten your life expectancy.
Black Powder
Black powder is a true explosive. Modern powders in general use today is classified as propellants and is relatively “tame” compared with black powder. Working with black powder requires an extra awareness on safety.
Almost all old side-by-side shotguns with external hammers were manufactured prior to de before nitro-powders became commonplace. Shotguns with internal hammers, proofed for black powder were quite common; therefore have someone competent explain the proof marks on your shotgun barrels to you. If your gun has Damascus barrels, then you should only use black powder.
Loading black powder is not a disadvantage. Black powder will give you the same velocity as modern powders, at lower pressure. A disadvantage of nitro- powders is that rapid acceleration takes place, which may lead to erratic shot patterns. This is why shock absorbers are built into the plastic wads between powder and shot. Black powder provides a gentle acceleration through the length of the barrel, reaching optimal velocity just before the shot leaves the barrel. For this reason, black powder, if loaded correctly, could provide a better shot-pattern.
Another advantage is the reduced recoil, giving a gentle shove and not a kick.
Over Powder Wads
Unfortunately, plastic wads cannot be used successfully with black powder. Black powder burns for longer and hotter in a barrel, melting and deforming plastic wads. Pieces of melted plastic get stuck on the inside of the barrel, resulting in a increase in pressure upon firing any subsequent shots. Apart from being dangerous inconsistent pressures also Another reason is that a roll-crimped 2¼inch cartridge ends up much longer than a regular star crimped nitro cartridge.
Stuffing a number of thick cardboard discs to form a piston and gas seal is also not an option, as it will damage the inside of your barrel. It is sacrilege to fire masses of cardboard wads in historical and valuable old guns. Most paper and cardboard contains substances like kaolin (clay) to give it body, volume and stiffness. This makes cardboard very abrasive and damaging to the inside of a barrel, even if it was waxed or lubricated.
Rather use compressed felt wads made from 100% natural fibres, usually from compressed wool. These are non-abrasive to the inside of barrels. The small cardboard gas seal disc between the powder and felt wad, as well as the cardboard over shot wad becomes negligible because of their size and the surface area exposed to the inside of a barrel.
You have to match the length of wad to fill the cartridge. Decide on your load, amount of shot and powder, then determine the length of wad required. Try buying a wad of the correct length. It’s a mission cutting wads to size. Can be done. You have to be able to cut each one exactly square and tp the same length. Recovered felt wads will also indicate whether it’s shape has been retained.