Doc Nickel helped a guy with his side by side shotgun to rifle conversion. The owner of the shotgun did not want a permanent solution. He wanted a convertible shotgun. What Doc came up with is rather clever.
He came up with an end cap for the shotgun. The one common issue is that most rifle conversions weld the barrels or the end cap in place.
By using these inserts the barrels are held in place.
With the inserts in place, the owner can adust POI and screw the endcape in place to hold the barrels where he likes. The inserts protrude into the shotgun barrel.
So now the rifle can be adjusted and the conversion is not permanent. The modifications can be removed and the shotgun can be used as a normal shotgun.