A magazine well funnel assembly is an integrated design including a mainspring housing portion and a funnel well portion attached to a firearm. The magazine well funnel assembly includes a set of funnel walls arranged to form an aperture shaped to accept a magazine and is bounded by a funnel rim on a side of the set of funnel walls opposite a plane of the aperture. The funnel rim is shaped in an arc on a side of the set of funnel walls adjacent to the rear funnel wall portion to increase the surface area of the funnel. A method of modification includes drilling a relocated pin hole in the firearm frame and inserting the magazine well funnel assembly therein. A base section of the firearm frame may be removed to preserve the same vertical length of the firearm compared to before the magazine well funnel assembly was installed.