A .58 black powder enfield isn’t shooting 900yds. Let alone hitting anything your “aiming” at
"William Pritchett developed the Pattern 1853 Enfield in the 1850s. The 39 in (99 cm) barrel had three grooves, with a 1:78 rifling twist, and was fastened to the stock with three metal bands, so that the rifle was often called a "three band" model.
The rifle's cartridges contained 70 grains (4.5 g)[3] of black powder, and the ball was typically a 530-grain (34 g) Boxer modification of the Pritchett or a Burton-Minié, which would be driven out at about 850 to 900 feet (259–274m) per second.
The original Pritchett design was modified by Col. Boxer, who reduced the diameter to 0.55 after troops found the original 0.568 too hard to load during the Indian Mutiny, changing the mixed beeswax-tallow lubrication to pure beeswax for the same reason, and added a clay plug to the base to facilitate expansion, as the original Pritchett design, which relied only on the explosion of the charge, was found to cause excessive fouling from too slow an expansion, allowing unburnt powder to escape around the bullet.[4] The Enfield's adjustable ladder rear sight had steps for 100 yards (91 m) – the default or “battle sight” range – 200 yards (180 m), 300 yards (270 m), and 400 yards (370 m).
For distances beyond that, an adjustable flip-up blade sight was graduated (depending on the model and date of manufacture) from 900 yards (820 m) to 1,250 yards (1,140 m). British soldiers were trained to hit a target 6 feet (180 cm) by 2 feet (61 cm) – with a 2 feet (61 cm) diameter bull's eye, counting 2 points – out to 600 yards (550 m). The target used from 650 yards (590 m) to 900 yards (820 m) had a 3 feet (91 cm) bull's eye, with any man scoring 7 points with 20 rounds at that range being designated a marksman."
https://en.wikipedia.org/wiki/Pattern_1853_Enfield
"P53 British Enfield Rifle:
• Caliber: .58
• Cartridge: .577 ball
•
Maximum Effective Range: 1,250 yards (with accuracy)
• Maximum Range: 2000 yards (20 football fields)
• Weight: 9.5 pounds
• Bayonet: yes"
https://www.independentgreys.com/2nd-md-rifles.html