copying record confidence permissions

i'm duplicating record folder folder b following perplexing duplicate record permissions. here simple stairs i'm using:

1. copyfile(source, target)


2. getnamedsecurityinfo(source, group_security_information | dacl_security_information)


3. print source sd controlling convertsecuritydescriptortostringsecuritydescriptor


4. setnamedsecurityinfo(target, group_security_information | dacl_security_information)


5. getnamedsecurityinfo(target, group_security_information | dacl_security_information)


6. print aim sd controlling convertsecuritydescriptortostringsecuritydescriptor

at #3 i sd:

g:s-1-5-21-1454471165-1482476501-839522115-513d:ai(a;id;0x1200a9;;;bu)(a;id;0x1301bf;;;pu)(a;id;fa;;;ba)(a;id;fa;;;sy)(a;id;fa;;;s-1-5-21-1454471165-1482476501-839522115-1004)

at #6 i get

g:s-1-5-21-1454471165-1482476501-839522115-513d:ai(a;id;0x1301bf;;;pu)(a;id;fa;;;ba)(a;id;fa;;;sy)

the setnamedsecurityinfo advantage error_success, nonetheless law source aim record have same sds. since that? am i doing wrong here?