I have just completed new assembly on a Beretta receiver with a new Criterion .308 barrel. Most all the parts are as new and it is sitting pretty in a Boyd's stock set. The issue is when I use old IVI ammo, it will sometimes fire a double tap. It does not do it with Federal Match ammo so I am wondering if the issue is the ammo or some other gremlin. It feels good/interesting when two shots go off almost simultaneously but it is likely not a safe condition by any stretch of the imagination. Any ideas or suggestions of what I should be looking for besides a .308 bolt action to use up a fair bit of this old surplus ammo?