The Gurus knew what will happen in the future with technology (guns get better with tech), the Gurus are Akal Purakh themselves, but Akal Purakh blessed us with a kirpan as a Kakkar, even though guns were used by the Khalsa Panth in Satguru Sri Guru Gobind Singh Sahib ji Maharaj time. If the Gurus wanted, they could have eliminated all the enemies of the Khalsa Panth in a split second. But they stayed inside of Akal Purakh's Hukam. In the past Saints have offered to help the Gurus with their shakti, but the response was always it is Akal Purakh's Hukam for this to take place. Sant Baba Gurbachan Singh ji Maharaj, knew Sri Darbar Sahib would be attacked in 1984, but Sant ji did not go out of Akal Purakhs Hukam to stop the attack. The Sant's of Akal Purakh know the future and so does Satguru. But Satguru still blessed the Sikhs with a Kirpan as a Kakkar and never told us to change the Kakkar. Satguru has told us to keep shastar on us, but a shastar (gun or any other weaponed, even a sword) can never be referred to as a Kirpan. A Kirpan is only given to the Sikhs at Amrit Sanchar.