I am shooting a 7mm Remington Ultra Mag. and I am shooting it hot using Retumbo and a 160gr AccuBond. I don't expect a long barrel life but does anyone have any direct experience with this caliber and barrel life? How many rounds should be reasonably expected fron this catridge and a factory barrel? the present barrel has about 800 rounds through it and shoots very well indeed. I would not expect better from anyone's custom barrel but don't know how long to expect it to last. When the time comes the rifle will get a Hart barrel of the same caliber.