Hi,
If you are going to go all the way to restock a Miroku Bess, I suggest replacing the butt plate and the trigger guard. You cannot produce a historically accurate Bess with those components. Look at the photos below to see the problem. They show an accurate copy of a short land butt plate against a Pedersoli stock. The Miroku is the same, even worse because the extension is so misshapen.
Do not use the Miroku stock as your guide. It is too small in the butt, wrist, and lock area but too large in the forestock. It also has too little drop at heel. Here are some key dimensions :
The height of the butt plate from top of the tang to the toe must be at least 5 1/8", with 5 1/4- 5 3/8" better. You can get correct plates and trigger guards from TRS and Track of the Wolf. The TOW plate is a long land plate but the tang can be shortened and reshaped to make a correct short land plate. When using Miroku parts the barrel will be a bit small at the breech. The originals are 1 5/16" - 1 3/8" in diameter so you have to compensate by keeping more wood on the sides of the lock panel area to preserve the correct width of the wrist. The web of wood between the barrel channel and ramrod groove should be at least 5/16" - 3/8" at the muzzle. It follows the bore more or less and may even break into the barrel channel on at the breech on original guns with full sized and flared breeches. With Pedersoli and Miroku barrels I arrange it so it allows just enough clearance for the forward lock bolt. That means at the breech, the hole is about 1/8" below the barrel channel. The ramrod hole is 1/4" in diameter and the groove can be a little larger.
Unfortunately, after you are done, you still have the goofy lock markings and a you might want to make a new larger side plate from sheet brass because the Miroku version is way too skinny. Here are some key dimensions from a short land Bess used by the 20th regiment of foot and likely captured at Saratoga.
Barrel diameter at breech 1.35"
Barrel diameter at muzzle 0.91"
Lock length 7"
Lock height behind pan 1.23"
Butt plate height 5.27"
Butt plate width 2.08"
Length of tang 3.72" from heel screw
Wrist height at end of comb 1.75"
Width at end of comb 1.63"
Height at breech 2.25" without including the guard
Width at breech 1.85"
Width behind lock panels 1.86"
Height behind lock panels 1.9"
Distance from breech to end of comb 7.75"
Height of wrist at end of barrel tang 2.15"
LOP 13 1/4" some will be longer 13 5/8" to almost 14"
Height of stock without barrel just behind the swell 1.49"
Width of stock just behind swell 1.42"
This is a short land made from a combination of Miroku, Pedersoli, and TRS parts. The first photos show the unfinished musket next to a Miroku stock.
The finished gun.
Note in the next to last photo above, the lock and side plate panels flare a little toward the rear. They are mostly parallel on the originals. The flaring was the compromise I made because the repro barrel is smaller at the breech than the originals and the flaring preserves the thickness at the wrist. That thickness and height is what makes the gun look and feel like the real thing, something missing on all the commercial repros. The decorative rings at the breech were hand filed on the originals and only cover the top 1/3 of the barrel. It makes it easier to inlet the Miroku barrel if you file away those rings on the bottom half of the barrel. Also pop off the second barrel lug from the muzzle. It is just soldered on. Move it back on the barrel so it can be used to support the screw for the forward sling swivel. That swivel is mounted just in front of the second ramrod pipe so it rests on the pipe when the gun is held vertically and does not block the ramrod channel.
dave