You certainly could be correct it seems.

My inclination was to attribute the impact change to the difference in tension of the fore arm screw being tighter today.

There were two other changes i forgot to mention. One is i changed how i was holding the rifle, so i could hold it tighter to my shoulder. The other is i used a different ram rod, with a spin jag today, but the first two days the ram rod didn't have a spin jag, it was supposed to spin in the handle, and it didn't seem like it was.

Yep, i did a poor job of controlling the variables.