This is Sarah. She is 15 and left-handed, so a light 9mm carbine with left-hand ejection is a reasonable long gun for her. The carbine is topped with a 3x scope zeroed at 50 yards.
With this being the reticle, what holdover is necessary to hit a clay at 150 yards? We corrected by observation of impacts and found that the middle of the stadia lines (two down) was exactly right for 150. I am guessing the top line is good for about 110. From prone, she was hitting clays better than 50% of the time using Russian steel-cased ball despite strong cross-wind. Firing on a brown grocery bag (for low contrast against the wilted grass of the backstop) as the target, she put the entire magazine into it. A grocery bag is about the same size a goblin torso.
The light on the carbine can be used as a backup aiming device. It also has iron sights but they cannot be used without dismounting the scope. 45 degree rails might be a good idea for it to enable aiming with BUIS around the scope.
The carbine ran reliably even with junky ammunition. It was accurate enough to hit point targets at 150. The bottom mark would correspond to 180 or so and the opening at the bottom to around 200. Which wouldn’t even reach out to her mailbox from the bedroom window, but should be entirely adequate for most defensive needs. For 250 yards, centering the head in the opening would get a center mass hit.
She did shoot my .308 Vepr and hit 75 and 100 yard clays with just a red dot, so reaching out to the mailbox isn’t beyond her girlish efforts. And I am just glad that yet another person out there is capable of fending for herself in case of feral dogs or goblins. While a rifle caliber would be better, 9×19 is quieter, cheaper to feed and kicks less.