point in the investigation in the origin of true black powder and the first propelling weapons is that before the first reliable instance there are always other possible
instances. The earlier the reference, the more unreliable, as a thumb rule. This just lies in the nature of looking into origins, as things do not come ready-made on earth, but evolve evolutionary. With that mind:
So when was the solid proof or recording (meaning accurate % of mixture) of gun powder for the Arabians? So far I see 1280
Al-Hassan: 1270 - 1280
in the book of al-Rammah, whereby his introduction suggests that the black powder formulas may be well older.
So when was the solid proof or recording of cannon or guns (not including firelance which was more of a flame thrower) for the Arabians?
according to Ibn-Khaldun (fl. 14th century). That date was given by me above as first date, as I personally and subjectively view that as reliable, since the author is credible and near-contemporary and the description of cannon is explicit.
However, al-Hassan also writes "In 660 / 1262
, King Alfonso X of Castile succeeded in conquering the city of Niebla. The siege was not easy either for the besiegers or for the Muslim inhabitants due to the strength of the town’s defences, so the siege lasted nine months and a half. It is reported that Almohads in defending the city used machines that resembled cannon, which projected stones and fire accompanied by thundering noises. Some Spanish histories consider that this was the first time that gunpowder had been used in warfare in Spain."
Still earlier: "Four Arabic treatises describe or mention small portable cannon. All these treatises report that cannon were used in the battle of `Ayn Jalut in Palestine in 1260
between the Arab Army and the Mongols, in which the latter were defeated".
The earliest, "Peter, Bishop of Leon, reported the use of cannon by the Arabs while defending Seville in 646 AH/ 1248 AD