honestly ive shot multiple firearms that have larger powder to bullet grain ratio and at a semi and fully auto setting,, and have gone well over 3000 rounds, it comes down to the quality of the metal and manufacturing , and the time and effort put in to cleaning the firearms, i clean all my weapons every 3 months whether i shoot them or not and i always do a proper barrel break in to all my new weapons. i have heard of people get 2000-3000 rounds with a 22 250, but like i said u get what u pay for and if you dont know how to maintain a weapon, or lack there of well than your weapon will not perform to its full potential and will not last as long. hey guys thanks for your info, i actually knew the outcomes of my qustion, i was just doing a survey on differnt caliber of guns and there reliability and life of the weapon thank you!