GunsAmerica.com, Collectors Firearms and Legacy Collectibles are some places that have World War II rifles for sale. The collectible firearms dealers have a wide variety of rifles available from both Axis and Allied armies. Some of the companies are auction services similar to eBay, while some sell their own inventory.
GunsAmerica.com is a classified ad and auction site where sellers list many different World War II rifles for sale, including numerous Springfield Armory M1 Garand rifles and M-1 carbines from several different manufacturers. Authenticity is up to the buyer to verify.
Collectors Firearms has a large inventory of World War II guns in stock from many countries including German Mauser, Danish Danzig and British L59 A1 rifles. Each product has a detailed verification of age and authenticity description provided. Legacy Collectibles has a few World War II vintage American and German rifles in its inventory such as M1s, Mauser K98s, Mossberg M44s and Walther G43s.