Don’t Ever Change …
Another fix (you knew this was coming) — the fixed-power scope. In a fit of experimentation, I just took a tape measure to scopes on rifles in my rack. Length of ocular assemblies ranged from 1-3/8" on an old Weaver B6 to 4" on current Swarovski Z6 and Z8i scopes. Lest you scoff at the B6, thin as a garden hose and clear as pond water, I’ve used it recently on an equally ancient Savage 340 in .222 to drill a group smaller than its tiny objective lens. But to bring comparisons into a single era, I also taped an M8 6x Leupold. Its eyepiece measured 2-5/8". Shortest oculars on variables belonged to Weaver 2-7x and Leupold 2 ½-8x sights: 3-1/4".
Incidentally, these figures are from scopes whose reticles are focused for my eyes. Why does it matter? It doesn’t on vintage scopes with ocular housings rotating on a threaded tube secured by a lock ring. The length of such an assembly doesn’t change as you adjust it to focus — as it moves rearward, it clears more tube so the scope can be repositioned to compensate. But most scopes these days feature fast-focus (European) eyepieces with internal helical threads. As you bring the lens closer to your eye, the housing stays fixed on the tube. Running the lens rearward increases the effective length of the assembly.