Interesting backstory on the gun. At the time the switch to the Gatling was made, in 2003, LM was convinced they had weight margin to play with. They were also thinking of a mod that would have allowed the B to carry 2K JDAMs (which could probably have been recovered VL in temperate conditions and/or with daytime reserves). And the Gat was assessed as having lower life costs relative to adding a new caliber to the Navy/AF logistics system.
They took the decision and then found out about the weight. The F-35A now has that giant wart above the R/H inlet, the gun pod has about two bursts of ammo, and they need a new round anyway...