Single load one and then load by letting the bolt fly. Eject both rounds without firing and then look at the primer.DaveB wrote:Don't most manuals caution against single-loading rounds into the chambers of ARs? The floating firing pin means that there exists the possibility, however remote, of a slam fire.
Both will have a small indent, and both methods will slam the firing pin in to the primer, doing it the fast way might actually cause more energy to be transferred where as single feeding you might close the bolt slower.