Re: .32 Cal Flintlock???
Before I build anyone a .32cal I always make sure they understand that the .32 can, and often does, have some little quirks to contend with. In no particular order... More often than not, people tend to seriously overload the .32, the ball is a mere 45-50 grains and doesn't need a whole lot of powder to push it, a 10-20gr charge is often more than sufficient and will normally produce the best accuracy. Quite often you'll find that 2F will burn much cleaner than the smaller 3F. When it's cold and dry, the smaller the bore, the more apt it is to foul to a point that will require swabbing between every shot. The balls are small and hard to hang onto especially when it's cold so I strongly suggest using a loading block if you have even slight dexterity issues. Every barrel is an individual unto itself and some are more picky than others to the point that dumping vs. pouring the powder charge into the bore can be enough to wipe out accuracy. A .50cal won't really notice a ±3gr variation in the powder charge but a .32 or .36 can be drastically affected by an even smaller charge variation. The balls themselves must also be sorted by weight to obtain the most consistency.
I tell these things because if the purchaser does not understand the fact that smaller bores require far more attention to detail than larger bores, then they are quickly disappointed with the purchase. Personally, I like the .32, if I didn't, I wouldn't have built two of them for myself ... however ... I tend to favor the .36cal for an all-around small game & varmint hunting gun as well as a plinker/paper puncher. With other than a head shot, the .32 will wipe out the meat on a squirrel just as bad as a .36 will but the .36 will give a little better shot placement consistency at longer ranges for woodchuck and turkey hunting (slightly heavier ball counters wind drift and thermal currents a little better)
Another thing to consider is that most ML barrel makers only run .32 barrels once per year and if you don't have your order in several months before the production run is started, you're going to wait until the next run. Unless you like a very heavy gun, you'll want a 3/4" OD barrel in either .36 or .32 and you may also want to consider a tapered or swamped profile if you're going with a longer length barrel (greater than 32") such as in a long rifle configuration. In most cases you can get a 13/16" OD .36 x 32" to balance out nicely but it primarily depends upon the combination of rifle style, LOP and furniture as to if you may need to add some ballast in the butt or not.
Please don't take this as anything more than an FYI post, as I said, I personally like the .32 and .36 and every other caliber for that matter but I far too many people have been disappointed with smaller caliber ML's simply because they were expecting them to be as forgiving as their .50 or .54 and they are not.