Library photocopying generally falls under the Fair Use clause -- so long as you are photocopying for private use, then it's probably within the Fair Use terms; additionally, libraries are absolved of any legal ramifications of what their patrons do in regards to copyright. You can read more about it
here.
Technically, making a photocopy of something from a magazine for someone else (i.e. not for yourself, and you're not doing research for the person) violates copyright law, as you are distributing the work without the permission of the copyright holder.* But, realistically -- if the issue is no longer available for purchase, and you're not selling the copies, then it's not a big deal. It's the difference between the letter of the law, and the spirit of the law -- the company in question who holds the copyright is not going to be hurt in any way by your making the copy; they're not losing money, customers, etc. by your actions. You're not going to be hauled in front of a court for making the copy. If it were me, I'd do it, and feel no guilt -- if the issue was still available for purchase, that would be a whole other matter.
* I am not a lawyer, just a former librarian who has read a lot about copyright.