sigh.....
ok here we go again
The Enfield is specifically exempted as well from 5 round mags because someone writint the legislation figured out that after WW1 there were several trial and some production enfield semi autos that used the 10 round mags. The same mags that fit in bolt action enfield
oh and as a side they would also be able to us the 20 and 25 round 'trench mags' from WW1
So if they had not included the enfield mags (not the rifles) all 10 round enfield mags would have become prohibited devices

because somewhere in a museum there are semi auto enfield rifles.