Thompson Center Omega Z5 question???????????????????

[moose]

i bought a NEW Thompson Center Z 5 muzzleoader in 50 cal. what the difference between the Omega Z 5 and the Omega, both have  blued barrell and black comp. stock?? thanks for all replies.......Moose ( Cabelas has them both one is like $ 319 for the z5 and the Omega is $399, i bought mine private sale)