Odds of a discharge in a detached AR upper receiver?

[Spartan198]

Something I never thought about before but just started wondering about now.

If I detach the the upper receiver with a round chambered, what are the odds of it discharging?

[commando552]

Originally Posted by Spartan198

Something I never thought about before but just started wondering about now.

If I detach the the upper receiver with a round chambered, what are the odds of it discharging?

How do you mean, with the firing pin somehow being hit forward with the lower already detached? It should be exactly as drop safe as when fully assembled, and supposedly ARs are drop safe-ish due to the very light firing pin, although it will dimple the primer. As for the rear of the firing pin being struck by something, an AR-15 will be a lot safer than other designs as the firing pin is shrouded by the rear extension of the bolt carrier.