If you got 120 volts of current on each leg of a 50amp breaker but only 25v on each wire going into the stove outlet ,what could be the problem?
You do not note where in the world you are, so this is tricky to answer well.  In the US each screw terminal on the 50amp two pole 240V breaker should measure 120V to ground or neutral, and 240V terminal to terminal.  At the range itself there should be an outlet with four openings.  The two small rectangular pins opposite each other should be about 240V as the meter is showing in the below image, and the rest of the pins should be about 120V relative to each other.  If the voltage is off by more than a few percent on any of the measurements, there is probably a break in the wire of one or more pins.  With a voltmeter it is possible to read voltage that has leaked from other sources, so low numbers should generally consider to be open circuits.



You may have to trace the wire through the house and figure out what has been done. Often you'll find that some previous owner rerouted it for a new electric dryer or hot tub (if there was a gas stove there and the range plug was unneeded at the time).  For your own safety I recommend contacting with a locally licensed electrician for repairs.