There's a lot of engineering voodoo that goes into making a rifle work well and fire accurately. The length of a rifle's barrel and how it affects the velocity of the bullet is one of those major factors. In this post, I explain a bit of the physics involved here. But the real meat of the post is comparing three different barrel lengths, their ballistic trajectories, and how it might affect what zero you choose.
Trajectory Validation again. Strelok Pro.
Throwback Thursday: Long-Range Shooting with the AR-15 - The Shooter's Log
Gamo Swarm Maxxim G2 .22 Cal Multi-Shot Pellet Rifle : Sports & Outdoors
Preliminary Marksmanship Instruction
Best AR15 Zero Distances for 16 inch and 10.5 inch Carbines - The New Rifleman
What Distance To Zero A Red Dot On An AK-47
Make faster Hits and Improve Marksmanship with Your Point Blank Zero
New Zeroing Procedures
Barrel Length, Trajectory, and Learning Your Zero - Everyday Marksman