COLT LIGHTNING RIFLE PROBLEM ?????

I have 4 colt lightning rifles 2 in 32/20 with dust cover over the ejection port and 2 in 38/40 with open top receiver. my question is on the 2 32/20 if the hammer is cocked the slide is locked and you have to let the hammer down before you can work the slide action . on the two 38/40 even with the hammer back you can still work the slide . In looking at the parts on both there is a differance in the rear end of a part called the magazine gate. Is this a worn part or defect on my 2 38/40 or is this a function of two types of colt lightnings Thanks for any help you can give me I want to shoot them but can't decide if their LOCKUP is safe