While Miroku Bess lock parts are VERY robust, they are also much cruder than the Pedersoli. That means unless someone has already done a Trigger Job on them or the parts have been very well "worn in," the Trigger Pull is normally going to be VERY heavy and have creep and other annoyances in the feel of the trigger pull. That makes it difficult to get the best accuracy out of them. Having noted that, they can be fixed for a pretty good trigger pull by someone who knows how to do the work.
Since all Miroku’s are a bit long of tooth, I would carefully inspect the Internal Lock Parts for any cracks/damage. The ideal situation would be if you could completely disassemble the lock and inspect all the parts for damage that might otherwise be hidden. This is important as lock repair/replacement parts have run dry years ago and repair/replacement parts have to be custom made.
The fit of the bottom of the Frizzen to the Top of the Priming Pan often has too much gap and the priming powder can fall out when re-enacting or hunting. This can be repaired, though it takes some time to correctly fit the parts together so the Priming Powder stays inside the Pan.
The “flattened/squashed in” Trigger Guard Bow has been noted that when the first Bess was sent to Miroku for copying, the Trigger Guard Bow got damaged/flattened in shipment and the Japanese copied it that way, not knowing any better. Not sure if that story is true or not, but every Miroku I’ve seen has the flattened Trigger Guard Bow. That can cause a problem if the bottom of the trigger hits the inside of the Trigger Guard Bow and “mysteriously” cause the Sear to sometimes catch on the Half Cock when the trigger is pulled. Simple solution is to shorten the bottom of the trigger a bit so it doesn’t hit/drag on the inside of the Trigger Guard Bow.
Be prepared to need a Flint that is one or two sizes SHORTER than one would normally think to use in these Big Locks. The geometry of the Cock to Frizzen is a bit different than Pedersoli’s or Original Besses and that caused a lot of people to have problems with misfires in my Re-Enactment Unit, until I identified and corrected the problem for them. Once I found the correct size for each Miroku Musket, I wrote down the size/dimension of the flint that worked best and strongly suggested they keep it secure to use it when they needed more flints. Having said this, once one finds the proper length of flint for the Musket, many of them will take up to even remarkably poorly shaped flints and still be sure fire.
Since you plan on mostly shooting it live fire, you will want to inspect the bore carefully for heavy pitting. Some pitting won’t matter and can be fairly easily polished out. Best to have a tiny Maglite flashlight that will easily slide down the bore and illuminate the bore, so you can inspect the bore condition. If it looks like a Sewer Pipe in the barrel, I would not plan on using it for Live Firing.
When the Miroku’s were first imported, I looked at them as a Crude and poor copy of a Brown Bess. However, I’ve come to see though they are a bit of an “Ugly Duckling,” many of them have given years of good service. There is no doubt in my mind I would normally pick a Miroku Bess over any of the India Made Muskets, especially as the lock parts of the Miroku Bess are made of much better steel and normally hardened/annealed correctly.
Gus
