The Speed of Biju Bombs
Consequently to the previous threads, the speed of the
Juubi's own Biju Bombs - being significantly more powerful than Gyuki's Biju Bombs - would also be faster than light, and yet there are scenes that would strongly indicate against that assumption.
In Chapter 613, the Juubi undergoes its evolution into its second form and
begins spammning long-range Biju Bombs to rain down in distant locations. The last of these is aimed for the Allied Shinobi Forces' Headquarters located in the vicinity of Kumogakure. We then get an extensive sequence where
the sensory shinobi realize the target of the Biju Bomb, relay it to the others, they discuss the situation and then Shikaku has the telepathic ninja relay his plan to beat the Juubi to everyone on the battlefield before the Biju Bomb lands. We can then see the explosion in the distance and Madara remarking "
Finally got them."
For reference, the area where the Juubi is - where the alliance is fighting it - is indicated by the red arrow. The Allied Shinobi Forces' Headquarters is highlighted by a purple arrow.
Our
currently accepted value approximating that distance is around
700 kilometers, and even with other methods it is
at-most around a couple thousand kilometers.
Remember that lightspeed means
a projectile could circle the Earth approximately 7.5 times in one second.
But here we have multiple characters conversing each other, being shown in contemplation, coming up with ideas... and then to end it off, Madara remarks that they 'finally' got them after waiting for the Biju Bomb to land. This is not the kind of remark one would make if he was just waiting for a hundredth of a second. There is significant travel time for that amount of distance.
While it's a common convention that "Talking is a Free Action" and characters can execute high-speed maneuvers while still speaking normally, this goes well beyond just a line or two. These are full-blown conversations that don't make any sense if an FTL projectile is crossing so short a distance.
The much stronger Juubi's Biju Bomb being this slow should call into question Gyuki's Biju Bomb being assumed to be so fast.