If by "Jungle Carbine" you are referring to a Lee-Enfield, then you are right, it will be limited to about 100 yds due to its penchant for scattering rounds randomly
yep, was only good at what it was designed for.
if you like the look but want a real huntr, get a "sporterized" No4.
lots to be had for cheap.
pie plates at 500 yds are no problem with steel sights.
the original No4 have the pop up sniper rear sight, adjustable out to 1300 meters.
just be careful with the milsurp ammo.