Stevens 100E Series K extremely hard to work bolt

I bought a Stevens 100E Series K used from my cousin. I haven't been able to get in touch with him since for other reasons... but anyway. I cleaned the gun and everything looked good. The bolt was smooth and I dry fired it a couple times. When I took it to the range for the first time, I chambered a round, locked bolt down and went to pull the trigger and only heard a click. I found out that the bolt handle was not all the way pushed down, and needed to be forced down about another .5". Once fired I had to stand up and really pull the bolt handle hard to break it free. chambered another round fine, but was very very hard to lock the handle all the way down so it would fire. Its so stiff I had to stand up and really really pull on it. What could be the problem? there is not unusual wear visible on the bolt or anywhere else. I did however rotate some of the (dont know word) round pieces at are around the bolt. But Im pretty sure I put them back the way they were. The gun chambered and fired fine and ejected fine, just pushing the handle the last bit to allow it to fire was near impossible. help!

front action screw is to long. turn it out 1/2 turn and see if the bolt moves any easier.

loosen it?

Yes - it is possible to over tighten the front action screw so that it sticks through the bottom of the lug area and the bolt lugs rub against the screw.