From your description I would have to say you have a first type action Model 1919 NRA bolt action but one late enough to have the more opened ejection port. It should have a full length stock with sling swivels and a receiver sight made mostly from stamped sheetmetal parts. Your gun should have a dual firing pin, they jumped the serial numbers to 25000 when they upgraded the action about 1923~1924 with a faster lock bolt with a single firing pin.