The last step is to carefully clean the hardened Truoil out of the checkering using Forbys and a stiff brush, followed by a coat of linseed oil. The linseed will soak in and provide the classic matte contrast between freshly-cut checkering and smooth stock finish.
On to the metal parts, although much of this is out of sequence because the wood-metal work was largely done in parallel. The decision to bring this rifle back to firing condition was based on zero erosion to the thickness of the breech parts on both the inside and outside. And note how the breech plug is sculpted to improve ignition speed and contrast the rounded, loose-fitting threads of the breech plug with the sharp, tight-fitting threads on the drum, more indications of pre-1840 and post-1840, the barrel assembly being much older than the percussion conversion. As many of these old guns were stored loaded, in effect pouring and storing a thimble full of salt down the barrel and leaving it for a century, absence of outside corrosion means nothing. I would not attempt to shoot an old muzzle loader without a thorough inspection of all breech and bore surfaces.
To preserve the rifle, all the active rust has to be removed from the rust pitting and protective coatings applied and maintained to prevent future rust under normal storage conditions. I prefer to accomplish that with minimal disruption to the existing surface finish, but the two aims arent entirely compatible. As the bore is the most critical section to clean, I use a proprietary nitric acid rust remover bath and heat on the barrel, and a cold phosphoric acid bath on the remaining steel parts. The nitric acid solution is stronger and works faster, but leaves nothing in the pits to aid in preventing future rust. Hence once the barrel is removed from the acid bath, it must be stabilized immediately using oil or finish after a hot-water rinse.
The phosphoric acid, however, when soaked overnight, allowed to dry and scrubbed off using hot water to remove the bulk of the sludge, leaves a coating of phosphate salts in the pits to deter further rust. So after the nitric acid bath, instead of drawfiling the pits out, I spot treat the barrel and bore pitting with phosphoric acid before finishing.
I clean the bore using three grades of successive abrasive pastes (fine Clover followed by two grades of JB) on a succession of tighter bronze brushes wrapped in #0000 steel wool and patch-wrapped jags, using a rod with a centering cone so as not to abrade the soft barrel in all the wrong places.
The cleaned bore (right) still shows some minor pitting, however the tool marks remaining on the top of the lands indicate this bore was never very smooth to begin with, and I elect to stop here. If I decide to incorporate this rifle into my live fire demonstrations, Ill want to see how it groups before deciding whether to get more drastic with poured-lead laps and recutting the muzzles crown to optimize accuracy. So I touch up the nicks in the crown using fine needle and round files, and measure and record the twist of the rifling and diameter of the bore for selection of ball and patch sizes should the time come. The rifling twist is one turn in 27 inches, which matches the length of the barrel and another indicator that this is an early barrel. It wouldnt be until the 1850s that builders began to understand that patched round balls required much slower rates of twist for optimum performance. Until that became better understood, many traditional builders used one full turn in the length of the barrel.
I use a combination of phosphate bluing (Brownells Oxpho Blue) and plum brown combined with rubbing out with #0000 steel wool to bring the surface colors to a uniform appearance of age. In these photos, the lock plate and hammer on the right are in their natural, cleaned state untouched by chemicals, with the remaining parts colored to match them. The front sling swivel shown is a new replacement. Where traditional rust or fire bluing doesnt make sense, I like Oxpho Blue for jobs involving minor pitting. Its easy to apply, it doesnt after-rust, and it leaves a rust-protective phosphate coating more durable than other blues.
To prevent the problem of frozen pins in the future, I replace all three steel barrel lugs with brass, staking them in place for security using a punch. Plus I replace all five pins assembling lugs and thimbles to the stock with new, hardened pins. As the severe damage to the muzzle end of the stock was caused by the front swivel lug failing, I deepen its dovetail as well as stake and soft-solder it in a belt-and-suspenders approach.
At this stage I also center punch all the stocks pin holes I repaired using either wood or epoxy so I can drill through the stock and new lugs together, installing the barrel in one, continuous operation.
The pin holes are drilled using a hand drill where I have a good index or center punched, plumbed and drilled through-and-through with the barrel mounted using the drill press. Overlong pins are tapered on one end, blued on the driving end, driven through, trimmed, blued and driven flush.
Continued...
