Agree with the Master above. Short of abuse, I don't think you CAN shoot the barrel out of a Marlin 30-30. But a .220 Swift, with HOT loads, VERY brief barrel life. The throat will leave before the rifling- erosion from gasses. Depends on a lot of variables. I do not even want to THINK how many rounds have gone thru my SMLE with the 1915 date on the wrist. We had range guns for M-60 training that each gun fired about 4- 5,000 rounds a week. For about 40 weeks of each year. Parts wore out- but barrels held up well.