Keep your powder loads mild.
The Pedersoli Kentucky uses the nose cap to retain the forward part of the barrel in the stock.
Their method here is to have a small area of the wood sticking from the front of the stock.
This projection ends up being between the inside of the muzzle cap and the underside of the barrel.
A screw passes from the bottom of the muzzle cap, thru the projection and into the bottom of the barrel.
This design works OK as long as the powder load is not heavy or a heavy bullet is used.
If the recoil of the barrel is too great, that wooden stock projection has been known to shear off.
If your worried about this and you have some experience in installing barrel underlugs and cutting a clearance pocket for it, you can install a round pin thru the wood and the underlug to hold the barrel in place.
When I restocked my Pedersoli Kentucky pistol with this curly maple stock which I carved from a block of wood, I decided I would install a barrel underlug and pin the barrel in place.
You can see the location of the pin in the center of the star escutcheon.