Gillette black tip question

[asargangle]

I have a Black tip Gillette been shaving with it for a a bit more than a month now.
I started trying different razor blades to get a good close shave without razor burn
or cutting my face to ribbons.
The last two days I noticed something that made me want to ask a question....
Monday I put in a Feather blade, I loved, it felt great and got real close.
Then Tuesday (same blade and open the razor between uses to let it dry)
it felt like a different blade. It didn't get as close. I didn't change anything.
After trying to get closer a few times, thinking maybe my angle was wrong.
I loosened the blade a little then it worked better.
Which brings me to my question.
Can you/is it wise to loosen the knob a little to get a better shave. Kind of
making it adjustable. If so how much is too much and if not how tight should it be.

Also why would a blade act like that?
Thanks,
~Asar

 

[hdjj00]

This does work for some models. Even some of the original Gillette instruction manuals advize loostening the knob slightly to make the razor more aggressive. Some older adjustable razors use this principle/design to adjust the blade gap and exposure.