Whats in the racks at the North or South stores has nothing to do with whats available.
Rifles are shipped from a differnt area. Yes stock in the stores are limited but Service Grades are not sold out , just takes a month or so to fullfill order in mail order
Here is a cheap easy way to fullfill CMP's club membership requirements
The M1 Collectors, only $14 for a full year
http://www.m1collectorsclub.com/