I have tried 308 in mine with no adverse effects, so far. I have read the forums stating that 308 pressures are too high for the ishapore and have also read posts that say it is no problem as long as you are not pushing the velocity limits of a 308. Would really like to shoot 308 as that is what I have available. What have you guys seen? What have you heard? What do you think? I will not hold your opinion as gospel as I know a lot depends on the condition of the gun in question. I just want to know what, if anything, have the members seen or experienced.