Don't believe these were ever commercially produced, but rather developed to provide a centerfire alternative to the 25 Stevens rimfire. I've been working on an early tip up which has been converted to what I thought was the 25-10, but turned out to be a cross between a 25-10 and a 25 Hornet. The rim dimension is as the 25-10 and 25 Stevens, but the oal is that of the 25 Hornet. Neat idea as all three can be shot in this gun requiring only the rim of the 25 Hornet to be thinned. Question is this: Is the altered 25 Hornet then considered a 25-10 Long (if there ever was such a thing) a 25 Hornet or something entirely different?