The strain screw was intended to be snugged down tight & LEFT there. It is not a trigger pull lightener. Backing it out can & does reduce the amount of energy transmitted to the primer by the hammer, resulting in light primer hits.

One common problem with potential for disaster in backing it out is that it can continue to back itself out farther under continual shooting, and may fail to fire just when you need it to.

Don't back it out! Snug it & leave it.
Denis