Norinco 1911 has a forged, not a cast frame, like SAM's.
you say this like a cast frame is made of sand and crazy glue and forged is not
you should get over this and understand that both are near identical and each has its advantages and disadvantages
but both are apples one red and one green not one apple and one kiwi fruit
a excerpt from said reading material link below
Size and Weight—Steel castings are almost always lighter than their forged counterparts and the redesign from forgings to castings usually results in substantial weight savings. For example, a forged muzzle brake for a cannon anti-recoil system weighed more than 600 lb. The cast version weighed 400 lb and lasted more than three times longer.
a little reading on it
http://www.sfsa.org/sfsa/pubs/cvf/ecs.php
both the norinco and the SAM are very good entry level 1911's
i prefer the SAM
you don't
that is life
neither is better than the other just different
you happen to prefer the one that i don't good for you
really shooting is shooting and it doesn't matter if it's a 1911 a glock or a sig or a ruger or S&W
buy what you like and shoot the crap out of it and have fun
it's what i do
and when asked what it is that i am shooting i proudly tell them what it is and they are more than welcome to give it a try
this always makes for a good day at the range and a good way to make a new friend