Re: flintlock shotgun info.
I strongly advise against putting a smoothbore on a mass-production gun, they're okay if you want a smooth rifle but ain't worth a hoot for wing shooting because they're too heavy and slow.
If you're wanting a good fowling piece, you need to get a good dedicated fowler that's built to fit you as well as being properly balanced. If the balance or fit is off, it's not going to come-up or swing right.
As for loading, the two most common mistakes made are:
1- Overloading. Using far too much shot.
2- Method of loading. Trying to load it like it's a cartridge.
After nearly three centuries we're still moving 180° out of phase ... rifle bullets are getting light and faster while shotgun loads are getting heavier and slower - the exact opposite of what we should be doing! Two-hundred some odd years ago, the Brit's decided to say "screw technology and the facts, we'll just make bigger bores." Unfortunately, that lack of logic has stuck in a big way and has gotten even worse since the big-hair and big MAGNUM days of the 1980's.
There are people out who insist that they must throw 1-1/2+ ounces of shot from a 20ga and 2+ ounces from a 12ga or it's just not right because "you can't possibly kill anything without a MAGNUM". I freely admit to getting suckered in by the 80's big MAGNUM craze but testing quickly proved that no matter how big and bold the word "MAGNUM" was stamped on the box next to the "MAX dram eqv.", they simply don't work in the real world. There is only so much velocity one can obtain on a given payload mass before the safe operating pressures are exceeded and when the shot payload mass is increased, the pressure increases and in order to maintain safe pressure limits, the velocity must therefore be reduced. That is why ammunition mfg's went to "MAX", "SKEET", "FIELD", "UPLAND" and so forth in the "Dram Eqv" space on the box and now most mfg's have simply eliminated it altogether ... reason being, they don't want to make the painful truth so easily found. Check out most any ammunition mfg's ballistic data for their shotgun loads and you'll see quite impressive velocity ratings yet when pushed, they have no choice but to admit the numbers are intentionally misleading because they're using "special test barrels and chambers" and barrels with lengths of 34" or longer - that's only about 14" more barrel length than those stubby little "special MAGNUM turkey" guns have and it makes a HUGE difference.
Just take a minute and look at things from a reality standpoint. Shot pellets are nothing more than small round balls. We all know round balls lose velocity quickly over distance and thus is why in order to increase the effective range, one must either shoot bigger diameter round balls or maximize the muzzle velocity - the latter will not afford as much of a yardage gain as increasing mass which in turn increases momentum and it's momentum one needs to be concerned with in hunting ballistics, not velocity. When it comes to shotgun loads, we can obtain a fair estimate of performance based on pellet size and velocity at the time of impact, however, the one thing you'll never hear shotgun ammunition mfg's talk about is "impact point pattern density" (IPPD).
IPPD is the percentage of pellets within the effective pattern zone at a given range. To explain this, one needs to understand "shot string" which is the length of the shot cloud in the air from the leading most pellet to the trailing most pellet. On average, a 1-1/4oz 20ga 3" magnum cartridge load from a "full" constriction style choke has a shot string of 15-20 feet in length. The mid-point of the shot string is considered the "effective zone". The IPPD is taking a slice out of the effective zone and establishing the number of pellets as well as their dispersion within the circle. Thus, if we take a 1oz load of #6 shot and you can put an average of 4 to 5 pellets into the fatal zones of a flying pheasant, you have an IPPD of about 2% meaning that 98% of the total 225 total pellets in that load have missed the intended target. Wing shooting is all about upping the IPPD because the bird is only in one small section of the shot cloud at the time of impact. The only way to up the IPPD is to decrease the shot string length and the way to do that is by building the load to the particular gun just the same as is done with rifles and every shotgun, just as every rifle, will have a particular load it likes best. Shooting patterns on a static (non-moving) pattern board will not give you any indication of your IPPD, all that gives you is the total combined pattern density as you are seeing all the pellets from the leading most to the trailing most. Static patterns are a valid tool to identify patterning issues such as clumping, wandering and doughnut holes but are not effective in identifying how well that particular load will work for wing shooting.
Occasionally you will hear the term "square load" used and often in the ML community this is incorrectly defined as using the same volume of both powder and shot. The correct definition of "square load" is using a shot payload length in the bore that is equal to the diameter of the bore. Thus a 0.620" bore (20ga cartridge size is actually 0.615") should have a shot payload that does not exceed 0.620" in length and a 0.729" 12ga bore should have a shot payload not in excess of 0.729" in length. Granted there is a little fudge-factor involved but not a whole lot when it comes to obtaining the highest IPPD.
Another thing you'll rarely, if ever, hear mention is shot-drop factor. A typical load 1-1/8oz payload of shot leaving the muzzle at 1,200 fps will drop below the line of sight between 8.5" and 12.5" over it's roughly 1/4 second travel time to reach the 60 yard point. When you begin to factor in the combination of shot string length, shot-drop factor and IPPD, you'll quickly understand that the most effective shotgun load is one that combines the highest velocity with the best pattern control and highest IPPD and you just can't do that with magnum mass shot strings, some running in excess of 25 feet in length.
If you get a 0.620" bore (20ga ML) muzzleloader, you want to use shot charges with a mass between 1/2oz and 1oz and you'll find that most will produce the highest IPPD with a payload mass between 11/16oz and 7/8oz. In some cases you may need adjust the powder charge slightly above or below the equal volume starting point and it is always best if you can adjust the wad combination in such a manner as to allow for maintaining a higher velocity without giving up IPPD. In a 0.730" bore (12ga ML) you'll find that shot payloads in the range of 3/4oz to 1oz will provide the highest velocity and IPPD. Bore need not be "choked" to produce acceptable patterns to 35 yards, often times it is just a matter of spending the time building a load that works.
When it comes to loading technique ... pour the powder in slowly just like a rifle letting the bore act as it's own drop tube. Then insert the overpowder nitro card wad only until it is flush with the muzzle then set your fiber cushion wad on and push both in only far enough for the bore to accept the shot charge volume. Once the shot charge is in, set the overshot card wad on top of it and push the entire assembly down as a complete unit. Loading in this manner will help prevent trapping air between wads and especially between the OS wad and the shot charge as the wads, including the shot payload, can easily move back down the bore as you remove the ram rod - a gun fired without all components of the load firmly seated on top of the powder charge is likely going to explode in your face! Smoothbores, especially larger diameter bores including rifles, are more prone to "holding fire" so please avoid the "fast reload", take your time and wipe the bore between shots because it'll perform better and greatly increase the safety factor. It takes far less time and effort to swab then double or triple check to ensure the load is fully seated than it does to spend time in the ER getting sewn back together or living the rest of your life missing pieces of your body. You're not going to starve to death over a missed shot, you can always grab a mystery meat sandwich or slider at the gas station on the way home.
There are various methods of making shot cups and cartridges but in all cases, build the assembly at the muzzle and seat it all at one time. There are many different things one can use as a shot pellet buffering agent too but avoid anything synthetic as they will deposit very nasty fouling on the bore that will make loading difficult and shots extremely inconsistent. Don't be afraid to experiment with powder granulation size. Some bores will run great with 3F while others will work best with 2F or 1F and bore size vs. powder size does not matter despite what some of the myths say.
Do not get suckered into wrecking a good barrel with an excessively large expansion choke like the Tula or Jug style. Too much diameter increase will allow combustion gases to blow past the sealing wad cutting the shot, leading the bore and wrecking the pattern. Tula chokes must be engineered specifically to bore diameter, payload length, pellet diameter and velocity, there is no "generic" Tula style choke.
Sorry about the length of this, I'm just real passionate about the fowlers I build.