Have acquired a Sentry 1250 Fire safe (appears pretty old) with the door open but have no combination. How can I learn that combination or how can I reset it?

SOURCE: know combination, but cannot open sentry safe 1250

If you know the combination:

1) Turn the dial to the left a few complete rounds, then stop on 1st number.
2) Turning the dial to the right, pass up the 2nd number once, then stop on it on the next round.
3) Turn the dial to the left directly to the 3rd number then stop.

The handle should open now.

SOURCE: Father has lost safe combination to Sentry 1250.

try looking under the thesafe see if it has a reset button or u could read the sticker(if there is one) and see if u could get the store that u bought it from, to reset the combo

SOURCE: how do you open a sentry 1250 combination safe? I have the number

Locksmiths agree If your safe doesn't have a key, skip Step 3.
Turn the dial to zero.
Insert your sentry safe key and turn it until the plunger pops out.
Turn the dial to the left (counterclockwise) three times to the first number of the combination (pass the first number of your combination two times, stopping on it the third time).
Turn the dial to the right (clockwise) two times to the second number of the combination (pass your second number once, stopping on it the second time).
Turn the dial to the left to the last number (stop the first time on your last number).
Pull the handle down; cracking the Fireproof Sentry Safe open.