I can see I am in the minority here-- I say it by its letters -- W-A-S-R-10. My logic was that if I say AK, I don't say "Ack." If I say AR, I don't say "Arh."
Granted those aren't quite as long as a WASR-10. Like one mentioned on here, if I did look at one at a show or in a shop, I always say "Hey, can I take a look at that AK? Oh, its a Century."
(Not taking a stab at guys that own WASRs-- I just don't want one. I've had an SAR-1, and I have a Romanian "G" already along with a Polish and a Russian. I'm done on Rommy's for a while, I think.)
-- John