I have been wondering the exact same thing.
I bought a csutom shop 13" 25/35 barrel last month, with brake installed... got that barrel , a frame, Fajen custom grips & all for $325..just too good to pass up. Just got the dies/brass last week, and plan on making it talk soon.
Look in the great book "Wildcat Cartridges, Vol II, on page 272 at the 25/35 tomcat...not quite sure how this version compares to the 25/35AI, but i am guessing its close. From a rifle, its pushing 117's to about 2650fps..that should probably mean 87's at close to 3000 to duplicate the 250 Savage, but in a rimmed case for easier extraction, and at lower chamber pressure. After i shoot my 25/35 a but i may look for someone that can rechamber it.
I also shoot a 25 Bullberry, and in the same book, the author was getting 100 grain Noslers up to 2619 fps in this caliber. I have not clocked mine yet. Guess the 25/35 AI should be fairly similar to that one too.
If you do find any data on the 25/35 Improved, let me know, i like about anything with a .25 caliber hole down the barrel.
