Results of my patterning experiments (long and 'windy')
My favorite flintlock firearm for upland birds is the Pedersoli Mortimer 12ga. fowling piece. I use it for turkey and to a lesser extent for pheasant and ducks. After considerable testing and patterning, I finally worked up a good patterning load that yields approximately a modified choke equivalent patterning at 30 yards. This is excellent patterning from a true cylinder bore, but the load is rather unorthodox and uses several modern components. It is loaded as follows:
1. Use no more than 75-80 grains of 2F blackpowder. Combined with a 1-1/4 to 1-5/16oz shot charge, this yields a rather slow moving load, likely under 1000 fps. However at the necessarily shortened range of 30 yards max, pellet velocity and penetration still seems adequate on turkey necks. It still penetrates a tin can at 30 yards. A greater powder charge yields erratic patchy patterns, often blown out in the center, regardless of the components I have tried.
2. I always start every blackpowder shotgun payload with a 1/8" card for gas sealing, followed by a generous kidney-bean sized dab of soft lube (usually Crisco or goose tallow), and followed by a 1/2" fiber wad. When pushing these wads down bore, this combination has an excellent cleaning function, so that repeated wiping of the bore is usually unnecessary. I have shot up to 15 repeated shots without wiping, with the last being nearly as easy to load as the first.
3. The payload consists of a plastic 3" steel shot cup with a 20ga. 1/2" fiber wad placed inside to take up excess space and provide cushioning. Some additional lube is wiped around the outside and into the base, and then it is placed into the muzzle and pushed down to slightly protruding from the end of the bore. Next a 1"x2" Mylar shot wrapper is inserted, with the adjoining edges centered inside one of the slit leafs of the shot cup, top centered within the bore. I have noticed a slightly elliptical shape to some patterns that follows the location of the Mylar shot wrap seam, which is why I top center it, parallel to a stretched out turkey neck. The shot cup is then pushed in 1/2" beyond the end of the bore and the shot charge is added. I prefer to use hardened and plated #6 lead shot for turkeys. Finally and optionally, buffer is added. Place your thumb over the end of the muzzle and shake and tap the barrel with your knuckles to settle the buffer into the load. Then add the over-shot card and push the whole charge firmly down onto the powder.
Both the steel wad and the shot wrapper contribute to the tighter patterns, the steel shot cup contributing somewhat more. The buffered patterns seem subjectively somewhat more even, with less patchiness. It is interesting that recovered shot cups do not have opened leafs, and that the shot wrappers often are found 10 yards or more down range. I speculate that the stiff shot cup simply keeps the load together for a couple of feet or more beyond the end of the muzzle, giving some protection from the escaping gases behind, which otherwise can blow through and disrupt an exposed shot column. Also it may be that the presence of the 20ga fiber wad in the back of the shot cup contributes to a forward center of gravity for the whole charge, making it more aerodynamically stable for the first couple of yards, until drag pulls the shot cup back from the shot charge.
This combination yields very even and tight patterns in the Mortimer. I have taken 3 turkeys with it the past two years. It is not a simple load and requires several non-primitive components. However it yields very consistent and even patterns from the cylinder-bored gun, and eliminates the need to have choking or choke tubes done. I do not use this load when hunting grouse or pheasants, as it is too troublesome to carry all the various components. For this I generally just use a normal plastic shot cup or card and fiber wads and keep my ranges short, but I find I must still keep the powder charge under 80 grains for decent patterns.
I think it might be interesting to experiment with unslit shot cups and try perhaps a 3-slit instead of the 4-slit, or perhaps shorten the slits somewhat to see if the patterns can be tightened up more. The use of Hevi-shot would likely produce a tighter pattern and gain a few more yards of effective range. However, I must say my real preference would be to forget all the above and go back to my old hornets-nest paper wadding and mix of soft lead #5,6,and 7-1/2 pellets, keep my range max inside of 25 yards, and spend enough extra time in the woods to get the opportunities to make up for the shorter range. Retirement beckons.
D Warner
