The substitution of a new rifle for the old musket with which the sepoys had hitherto been armed entailed a different kind of drill; and in order that this drill should be speedily learned by the whole Native army, depots were formed at convenient places for the instruction of selected men from every corps, who, on becoming proficient, were to return and instruct their own regiments.  One of these depots was at Dum-Dum, and as early as the 24th January General Hearsay, commanding the Presidency division, reported to Head-Quarters that he perceived an ‘unpleasant feeling’ amongst the Native soldiers learning the new drill, caused by a belief instilled into them ’by designing persons, most likely Brahmins,’ that they were to be forced to embrace Christianity, and that for the furtherance of this object the new ball-cartridges received from the arsenal at Fort William were greased with the fat of pigs and cows, with the intention of violating the religious prejudices and destroying the caste of those who would have to bite them.

A little later various acts of incendiarism took place at other stations in the command, and Hearsay became more than ever convinced that there was grave dissatisfaction amongst the troops.  He therefore ordered a Court of Inquiry to be held to enable him to ascertain the real cause of the ill-feeling which so evidently existed.

In the General’s opinion, the statements recorded in the proceedings of this Court clearly established the fact, that the Native officers and sepoys were undoubtedly imbued with the belief that an unholy mixture of cow’s fat and lard had been used in the manufacture of the new cartridge, and he recommended that the rifle ammunition should in future be made up with the same description of paper that had always been used for the musket-cartridge, which, he conceived, would put an end to their suspicions and uneasiness.

The General, however, was told in reply that it was impossible to use the old paper for the new cartridge, as the bore of the rifle being much smaller than that of the musket, thinner paper was indispensable; and he was directed to inform the sepoys that the new paper, though tougher and less bulky, was made of exactly the same material as the old.  With respect to the lubricating mixture, he was to announce that the Government had authorized the preparation of a grease, composed of wax and oil, which was to be made up and applied to the cartridges by the men themselves.  These orders were carefully explained to the Native troops, but without any good result.  Their religious objection to the new cartridge was not removed, and they frankly acknowledged their fears.

On the 6th February an officer of the 34th Native Infantry at Barrackpore was informed by a sepoy of his company that the four Native regiments at that station, fearing that they would be forced to destroy their caste and become Christians, had determined to rise against their officers, and when they had plundered and burned their bungalows, to proceed to Calcutta and try to seize Fort William, or, if that proved beyond their powers, to take possession of the treasury.