The easiest solution is to use your muzzleloader forend if you have one. I know the mounting screws are different but simply remove the forend bushings from below your muzzleloader barrel and reinstall them below your rifle barrel and install the forend, it fits perfectly. Note, care must be taken not to strip those tiny screws that hold the bushings on and I recommend using a hollow ground screwdriver sized correctly.
Another solution utilizing a shotgun forend is still under investigation and requires using longer rifle forend screws and washers to install your shotgun forend to the rifle barrel. I also believe these solutions will apply to the laminate stocksets that I sell.
Until then be safe and shoot straight. Marty