I'm no expert... but I would guess that the barrel was cut down to 24 inches.  You should measure it to see if it is 30, 24 or 22 inches.  The muzzel looks a little squared off, although that may be because of the action.  Also, what is up with that sight blade?  Looks like it was replaced with a squared blade...  It should taper down in the front.  To measure your barrel by dropping a cleaning rod down the barrel with the bolt closed.  Mark and measure! 

My sportered 1898 was cut to 24" and a proper front sight base was (poorly) brazed into place...

Cheers,
Paul