I think the different wording is to make allowance and clarificationfor such rifles as the Encore when used in a muzzleloader configuration. My interpretation of their regs is that most any muzzleloader can be used, so long as it cannot be loaded from the breech as carried, so long as it meets the caliber requirements, so long as it meets the load requirements, and so long as it is used with open sights. Encores are legal muzzleloaders in Colorado.
3. MUZZLELOADING RIFLES
& SMOOTHBORE MUSKETS
a.
In-line muzzleloaders are legal.
b.
Must be single-barrel that fires a single round-ball or conical projectile
the length of which does not exceed twice the diameter.
c.
To hunt deer, pronghorn or bear, they must be min. of .40 caliber.
d.
To hunt elk or moose, they must be min. of .50 caliber.
e.
From .40 caliber to .50 caliber, bullets must weigh min. 170 grains.
f.
If greater than .50 caliber, bullets must weigh min. 210 grains.
g.
Shotshell primers are legal.
h.
Pelletized powder systems prohibited in muzzleloading seasons.
i.
Cannot be loaded from the breech in muzzleloading seasons.
j.
Only open or iron sights allowed in muzzleloading seasons. Scopes prohibited.
Fiber optic sights and fluorescent paints are legal. Artificial light,
batteries and electronic gear are illegal.
k.
Sabots are prohibited in muzzleloading seasons. Cloth patches are
not sabots.
l.
Smokeless powder prohibited in muzzleloading seasons. Black
powder and black powder substitutes are legal.
m.
Only legal muzzleloaders allowed in muzzleloading seasons.
Boldingthe "does not exceed twice the diameter" phrase was done by myself. Seems a silly reg to me, but it lingers.