thought i seen my name....a mauser is a gun manufacturer....a 7x77mm doesnt exsist...maybe a typo...for 7x57...and its not worht more than 200$ mausers are fairly comon...and its a spanish mauser...take it to a shop and have them check it out...prolly 8mm id my gess...and that will take ur g/fs arm off if u wanted a small gun for her....its bigger than a 06...

mauser06