If the rifle cartridge is the 308 Marlin Ex., I have no experience with that cartridge at all. If it is the 308 Win., I do. Since about 1962. This cartridge has been my deer hunting cartridge of choice for decades, though I have used others as well. With the 308 Win., I have taken deer cleanly from 10 or so yards out to about 350 yards. The key is to find the load that is most accurate in your particular rifle. Any decent hunting 30 cal. bullet from 150 gr. to 165 gr. should be ideal for the 308 Win. My personal favorites are the Nosler Partition or Sierra Game King. There are many, many more excellent hutning bullets out there as well.