A No.4 MK1 Lee-Enfield is
not an SMLE. Only a No. 1 MK III is an SMLE.
"...perceived as a dumb question..." No such thing.
"...the 300 yard battle sight..." Is about Mk VIII ammo with its 174 grain bullet at 2440 FPS. Pretty much, only. It also has to do with the height of the front sight blade and where you're holding on the target.
Anyway, at 50 yards the bullet is still rising on its trajectory arc.
Read this.
https://www.milsurps.com/enfield.php?pg=ti15.htm