I thought it was "be there fustest with the mostest".
And I still hold that cannon are well beyond Egyptian capabilites. The grenade idea, maybe, rockets, even more maybe, but no cannon and definitely no handguns.
Cannon aren't actually that difficult once you figure out the principle. Of course it's a different thing to build a powerful siege gun or a gun that carries over a mile and more - that requires serious metallurgical skill - but a basic antipersonnel cannon is within the capabilities of even fairly basic crafts. The main question is rather whether the Egyptians would digure out the principle and develop on it. Early and Middle Kingdom military could probably use it, but probably wouldn't have the nercessary technology yet. New Kingdom might have less incentive, but greater capability. By the time the late dynasties come, the technological capability would certainly be there or could be developed on an existing base.
Might someone be nuts enough to try to rocket-propel a chariot? I hope not...