google found this https://www.jimmiedeesairguns.com/rifles...d-1876-to-1938/

"On October 25th 1883, Haviland and Gunn filed U.S. Patent 290,230, “Process of Manufacturing Felted Slugs” with Quackenbush named as the assignee. This was three years after the partial buy-out by Quackenbush. I can only assume that Haviland and Gunn had developed their method of manufacturing felted slugs before going their separate ways. Perhaps Quackenbush acquired the machine as part of the sale and decided to protect his financial investment by raising the patent and naming Haviland and Gunn as the inventors. Certainly, the signatures of the inventors would appear to be from the same hand although it is possible that this was often signed on behalf of the inventor by the patent attorney. [29]

Quackenbush later improved on this design and raised U.S. Patent 358,984, “Apparatus for Manufacturing Projectiles” on December 31st 1886. Haviland and Gunn’s invention pressed a shot of lead to form the slug whereas Quackenbush’s invention included forming the shot itself from molten lead. [30]"

and with the patentnumber I find the patent also https://pdfpiw.uspto.gov/.piw?Docid=2902...%252Fpatimg.htm

the patent drawing makes me thinking if its possible to make old style spitzer bullets by swaging .22 pellet(who had the right weigth) with the rock chucker