Great care should be taken in converting a double barreled shotgun into a rifle. I saw an L. C. Smith converted into 30-40 Krag caliber come apart. The back of the receiver cut loose. Luckily no one was seriously hurt. I do not think that shotgun receivers are strong evough to fire rife loads. It might have burst because of the firing pin holes having too much leeway and the primer flowed back through the opening causing it to fail.