[colmurph]

Sounds like you also have a converted 1816 musket. The thing to remember is that the barrels were not made of steel. Steel did not come into use until 1894 with the advent of the Winchester Mod. 1894. The older stuff, even that which is marked "Cast Steel" is in reality malliable iron. You could have a gunsmith remove the old bolster, re-thread the hole, and install an oversized bolster. It is pretty difficult to restore a lockplate to Flintlock unless you get the proper replacement parts from someone like the Rifle Shop, that make exact replicas of replacement parts for museums, etc. The hole for the bolster would have to be welded by a gunsmith and a new vent hole bored through the weld. Re-converting to Flintlock does not alter the value of a converted musket. It still keeps the value of a percussion conversion (about 1/2 that of an original flint) even if the re-conversion is an excellent one. A careful examination of the lockplate and the inside of of the breech area of the barrel will show unmistakable signs of conversion. I'd go with a new bolster. When firing an original use a charge equal to the bullet, ie; 69 grains of FF for a .69 cal ball. DO NOT USE FFF in anything larger than .45 cal. as it will develop chamber pressures that are too high for the metal. If you have to use FFF, cut the charge in half. ie; 34 grains for a .69 cal.

One note of caution. If using Swiss Powder (a sporting grade of black powder) use half the normal charge of powder. GOEX and Elephant powders can be classed as "Blasting Powders" and are slower burning than Swiss. NEVER USE PYRODEX IN AN ORIGINAL GUN. Pyrodex is extremely corrosive, more so than black powder, and will start to rust the bore before you can get home from the range to clean it.