Colonial American Longrifle Kit — Step 1: Fitting Barrel and Tang to Stock
Video for this step: https://kiblerslongrifles.com/v/colonial-1
The barrel is designed to be 100% inlet and should require no additional work to fit it to the stock. The stock can change dimensions slightly with changes in environment (humidity), so there is some possibility that further fitting could be required. If so, a fine file held on edge can be used to slightly open up the barrel channel. Alternatively, abrasive paper can be attached to a flexible piece of metal.
It is a good idea to check the barrel-to-wood contact at the breech location with transfer color. Very little, if any, wood will need to be removed. It is very important that the breech position not change by any appreciable amount. Shaving a few thousandths to adjust the breech fit will not cause problems, but excessive wood removal will.
The tang will require a small amount of fitting. The inlet for the back and bottom of the bolster will need to be squared up.