Welcome, and thank you for your service!
You can't make an Ackley Improved out of it, but by PO Ackley's definitions, an Ackley chamber can shoot factory ammo, that can't be done with a fixed barrel since the barrel can't he set back as it can on a threaded barrel. You can have it rechambered to an Improved version, but must fire form brass using either a false shoulder(best) or seating hard into the lands to account for the excess headspace created when the chamber is reamed. I have a 280 Imp and a 35 Whelen Imp, plus a 6mm Rem AI which was originally a 243 Win, since the 243 is slightly small in dimensions than the 6mm Rem, it can fire the parent cartridge as well as the Ackley version, not so with the 25-06. The 25-06 Improved should show a gain of about 8½% over the parent cartridge.
Tim
http://www.4-dproducts.com/ackleychart.php