I recently purchased a 1974 colt python, blue with 4 inch barrel and in separate deal a colt python 1964 6 inch barrel and blue. These guns are unreal. when going out to shoot them I noticed the 1974 4 inch python pulled hammer and much stiffer trigger than the 6 inch which pulled and shot way way easier. any idea why they feel so much different when they are both pythons? thanks