Complex sentence: Among the favorites were the smaller German Luger in 9mm or even smaller Walther pistols, many of which were brought home by American troops returning from World War II. Others would trade their pistols for revolvers used by other personnel.
Split into simpler sentences: Among the favorites were the smaller German Luger Walther pistols, both chambered in 9mm. Many of these were brought home by American troops returning from World War II. Others would trade their pistols for revolvers used by other personnel.