The reason it feel like it is spring loaded is because it is. You are continuing to compress the main spring. It will return to the point where the sears engaged. Some people like a gun like this as it is impossible to load without it being cocked.
Personally I detest it & learned long ago to make certain both hammers cock & then be able to load without having to hold the barrels open.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra